Slow loading blog list page

I have a Runway installation running Blog 5.0 with ~800 blog posts imported from Wordpress. My blog index page is loading more slowly than my other Runway installs (on both dev and staging) and I'm trying to figure out why. This listing page is more complex than usual, with several perch_blog_custom() outputs as well as perch_categories() and perch_blog_authors(). Still, I don't feel that the page is heavy enough to be loading 6 seconds slower than usual.

Here is the debug message with PERCH_PRODUCTION_MODE set to PERCH_DEVELOPMENT:

Time    Δ   Debug Message
0.1005  0   [18] SELECT p.pagePath, pr.routePattern, pr.routeRegExp, p.pageTemplate FROM perch2_pages p LEFT JOIN perch2_page_routes pr ON p.pageID=pr.pageID ORDER BY pr.routeOrder ASC, p.pagePath ASC
0.1018  0.0013  Matched page: /blog, so not using routes.
0.102   0.0002  Using master page: /templates/pages/blog/index.php
0.1101  0.0081  [1] SELECT * FROM perch2_pages WHERE pagePath='/blog' LIMIT 1
0.1142  0.0041  Using template: /templates/pages/attributes/default.html
0.1153  0.0011  Using sub-template: /templates/pages/attributes/seo.html
0.1229  0.0076  [1] SELECT tbl.* FROM ( SELECT idx.itemID, main.*, idx2.indexValue as sortval FROM perch2_blog_index idx JOIN perch2_blog_posts main ON idx.itemID=main.postID AND idx.itemKey='postID' JOIN perch2_blog_index idx2 ON idx.itemID=idx2.itemID AND idx.itemKey='postID' AND idx2.indexKey='postDateTime' WHERE 1=1 AND idx.itemID=idx2.itemID AND idx.itemKey=idx2.itemKey ) as tbl WHERE (postStatus='Published' AND postDateTime<='2016-11-22 06:30:00' ) GROUP BY itemID, sortval ORDER BY sortval DESC LIMIT 0, 1
2.2912  2.1684  [25] SELECT DISTINCT settingID, settingValue FROM perch2_settings WHERE userID=0
2.2942  0.003   [1] Using template: /templates/blog/_post_top.html
2.2979  0.0037  [131] SELECT * FROM perch2_blog_authors ORDER BY authorFamilyName, authorGivenName ASC
2.307   0.0091  [1] SELECT * FROM perch2_blog_sections ORDER BY sectionTitle ASC
2.3091  0.002   [1] SELECT * FROM perch2_blogs ORDER BY blogTitle ASC
2.3149  0.0059  [1] SELECT regionID, regionTemplate, regionPage, regionRev AS rev FROM perch2_content_regions WHERE regionKey='Contact Information' AND (regionPage='/blog' OR regionPage='*')
2.3154  0.0005  [1] SELECT * FROM ( SELECT idx.itemID, c.regionID, idx.pageID, c.itemJSON, idx2.indexValue as sortval FROM perch2_content_index idx JOIN perch2_content_items c ON idx.itemID=c.itemID AND idx.itemRev=c.itemRev AND idx.regionID=c.regionID JOIN perch2_content_index idx2 ON idx.itemID=idx2.itemID AND idx.itemRev=idx2.itemRev AND idx2.indexKey='_order' WHERE ((idx.regionID=12 AND idx.itemRev=3)) AND idx.itemID=idx2.itemID AND idx.itemRev=idx2.itemRev ) as tbl GROUP BY itemID, pageID, itemJSON, sortval ORDER BY sortval ASC
2.3159  0.0004  [1] Using template: /templates/content/shared/_hero_social.html
2.3176  0.0018  [1] SELECT tbl.* FROM ( SELECT idx.itemID, main.*, idx2.indexValue as sortval FROM perch2_blog_index idx JOIN perch2_blog_posts main ON idx.itemID=main.postID AND idx.itemKey='postID' JOIN perch2_blog_index idx2 ON idx.itemID=idx2.itemID AND idx.itemKey='postID' AND idx2.indexKey='postDateTime' WHERE 1=1 AND idx.itemID=idx2.itemID AND idx.itemKey=idx2.itemKey ) as tbl WHERE (postStatus='Published' AND postDateTime<='2016-11-22 06:30:00' ) GROUP BY itemID, sortval ORDER BY sortval DESC LIMIT 1, 1
4.6368  2.3192  [1] Using template: /templates/blog/_post_hero.html
4.6469  0.0101  [1] SELECT setID FROM perch2_category_sets WHERE setSlug='blog' LIMIT 1
4.6474  0.0005  [35] SELECT main.* FROM perch2_categories main WHERE 1=1 AND setID=1 ORDER BY catTitle ASC
4.6504  0.0031  [35] Using template: /templates/categories/blog_list_nav.html
4.6831  0.0327  [130] SELECT tbl.* FROM ( SELECT idx.itemID, main.*, idx2.indexValue as sortval FROM perch2_blog_index idx JOIN perch2_blog_authors main ON idx.itemID=main.authorID AND idx.itemKey='authorID' JOIN perch2_blog_index idx2 ON idx.itemID=idx2.itemID AND idx.itemKey='authorID' AND idx2.indexKey='authorGivenName' WHERE 1=1 AND idx.itemID=idx2.itemID AND idx.itemKey=idx2.itemKey ) as tbl WHERE (authorPostCount>0) GROUP BY itemID, sortval ORDER BY sortval ASC
4.6885  0.0054  [130] Using template: /templates/blog/_author_list_nav.html
4.8423  0.1538  [6] SELECT tbl.* FROM ( SELECT idx.itemID, main.*, idx2.indexValue as sortval FROM perch2_blog_index idx JOIN perch2_blog_posts main ON idx.itemID=main.postID AND idx.itemKey='postID' JOIN perch2_blog_index idx2 ON idx.itemID=idx2.itemID AND idx.itemKey='postID' AND idx2.indexKey='postDateTime' WHERE 1=1 AND idx.itemID=idx2.itemID AND idx.itemKey=idx2.itemKey ) as tbl WHERE (postStatus='Published' AND postDateTime<='2016-11-22 06:30:00' ) GROUP BY itemID, sortval ORDER BY sortval DESC LIMIT 2, 6
7.0195  2.1772  [6] Using template: /templates/blog/post_in_list.html
7.0219  0.0024  [5] SELECT * FROM perch2_categories ORDER BY catTreePosition ASC
7.0548  0.0329  [4] SELECT regionKey, regionHTML FROM perch2_content_regions WHERE regionPage='/blog' OR regionPage='*' ORDER BY regionPage DESC
7.0555  0.0007  [1] SELECT * FROM ( SELECT idx.itemID, c.regionID, idx.pageID, c.itemJSON, idx2.indexValue as sortval FROM perch2_content_index idx JOIN perch2_content_items c ON idx.itemID=c.itemID AND idx.itemRev=c.itemRev AND idx.regionID=c.regionID JOIN perch2_content_index idx2 ON idx.itemID=idx2.itemID AND idx.itemRev=idx2.itemRev AND idx2.indexKey='_order' WHERE ((idx.regionID=12 AND idx.itemRev=3)) AND idx.itemID=idx2.itemID AND idx.itemRev=idx2.itemRev ) as tbl GROUP BY itemID, pageID, itemJSON, sortval ORDER BY sortval ASC
7.0559  0.0005  [1] Using template: /templates/content/shared/_footer.html
7.0588  0.0029  [5] SELECT * FROM perch2_pages WHERE pageNew=0 AND pageHidden=0 AND pageDepth >=0 AND pageDepth<=1 ORDER BY pageTreePosition ASC
7.0595  0.0006  [1] SELECT pageTreePosition FROM perch2_pages WHERE pagePath='/blog' LIMIT 1
7.0598  0.0003  [1] SELECT pageID FROM perch2_pages WHERE pageTreePosition IN ('000-003', '000') ORDER BY pageTreePosition DESC
7.0604  0.0006  [5] Using template: /templates/navigation/primary_nav.html
7.0674  0.007   Request time: 7.0672
7.0675  0.0001  Process time: 7.0663
7.0676  0.0001  Memory: 4.8611
7.0677  0.0001  
Array
(
    [type] => 32
    [message] => PHP Startup: Unable to load dynamic library '/usr/local/lib/php/extensions/no-debug-non-zts-20131226/ffmpeg.so' - /usr/local/lib/php/extensions/no-debug-non-zts-20131226/ffmpeg.so: cannot open shared object file: No such file or directory
    [file] => Unknown
    [line] => 0
)

(I only get the ffmpeg.so error on staging, but the site loads slow on dev as well)

This is my page:

<?php   
// 'load more' link
if (perch_get('ajax') && perch_get('start')) {
    perch_blog_custom(array(
      'template' => 'post_in_list.html',
      'count'=>6,
      'start'=>perch_get('start'),
      'sort'=>'postDateTime',
      'sort-order'=>'DESC',
      'paginate'=>false,
    ));
}
// begin page
else {

perch_layout('global/header',[
    'body-class'=>'blog-index'
]);
PerchSystem::set_var('blog-index', 'true');
perch_blog_custom(array(
  'template' => '_post_top.html',
  'count'=>1,
  'sort'=>'postDateTime',
  'sort-order'=>'DESC',
  'paginate'=>false,
));
perch_content_custom('Contact Information',[
    'template'=>'shared/_hero_social.html'
]);
echo '</div>'; /* closed from _post_top.html */
?>

<div class="section white-bg no-pad page-wrap">
    <div class="section split-hero dd-nav-wrap title-bg">
        <div class="container no-pad">
            <div>
                <div class="hero-title darker-gray-bg"><h2>Recent Posts</h2></div>
                <?php perch_blog_custom(array(
                  'template' => '_post_hero.html',
                  'count'=>1,
                  'start'=>2,
                  'sort'=>'postDateTime',
                  'sort-order'=>'DESC',
                  'paginate'=>false,
                )); ?>
            </div><div>
                <div class="hero-title dark-gray-bg"><h2>Search the Blog</h2></div>
                <?php 
                    perch_categories([
                      'set' => 'blog',
                      'template' => 'blog_list_nav.html',
                      'sort' => 'catTitle',
                      'sort-order' => 'ASC',
                      'paginate' => false,
                    ]);
                    perch_blog_authors([
                      'template' => '_author_list_nav.html',
                      'sort' => 'authorGivenName',
                      'sort-order' => 'ASC',
                      'paginate' => false,
                    ]);
                ?>
                <div class="section darker-gray-bg dd-nav-wrap alrightsans blog-search-wrap">
                    <form id="blog_search" action="/blog/search" method="get">
                        <div>
                            <label for="q">By Keyword...</label>
                            <input type="text" id="q" name="q" class="darker-gray-bg alrightsans" required>
                            <button type="submit" class="darker-gray-bg" ><span class="icon-arrow-right"></span></button>
                        </div>
                    </form>
                </div>
            </div>
        </div>
    </div>
    <div class="section light-gray-bg posts-in-list">
        <div class="container" id="loadWrap">
            <?php perch_blog_custom(array(
              'template' => 'post_in_list.html',
              'count'=>6,
              'start'=>3,
              'sort'=>'postDateTime',
              'sort-order'=>'DESC',
              'paginate'=>false,
            )); ?>
        </div>
    </div>
    <div class="section">
        <div class="container text-center">
            <span class="blue alrightsans" href="javascript:void(0)" data-url="/blog?" data-start="9" id="loadMore">Load More Posts +</span>
        </div>
    </div>
</div>

<?php
perch_layout('global/footer',[
    'scripts'=>'<script>jQuery(document).ready(function(){$("#blog_search label").inFieldLabels({fadeDuration:200});});</script><script type="text/javascript" src="/js/incl_blog-list-load.js?v=2016112101"></script><script type="text/javascript" src="/js/incl_dd-list-nav.js?v=2016112101"></script>'
]);

}

and diagnostics:

Diagnostics report
HEALTH CHECK

Perch Runway is up to date
PHP 5.6.24 is up to date
MySQL 5.5.52-cll is up to date
Image processing available
SUMMARY INFORMATION

Perch Runway: 2.8.32, PHP: 5.6.24, MySQL: mysqlnd 5.0.11-dev - 20120503 - $Id: 76b08b24596e12d4553bd41fc93cccd5bac2fe7a $, with PDO
Server OS: Linux, litespeed
Installed apps: content (2.8.32), assets (2.8.32), categories (2.8.32), perch_blog (5.0), collection_3 (2.8.32)
App runtimes: <?php $apps_list = array( 'content', 'categories', 'perch_blog', );
PERCH_LOGINPATH: /ifs-admin
PERCH_PATH: /home/mttstage/public_html/ifs/ifs-admin
PERCH_CORE: /home/mttstage/public_html/ifs/ifs-admin/core
PERCH_RESFILEPATH: /home/mttstage/public_html/ifs/ifs-admin/resources
Image manipulation: GD
PHP limits: Max upload 64M, Max POST 64M, Memory: 128M, Total max file upload: 64M
F1: 2edba60ed1f613d6dd804feb202456a2
Resource folder writeable: Yes
HTTP_HOST: ifs.staging.mytechtailor.com
DOCUMENT_ROOT: /home/mttstage/public_html/ifs
REQUEST_URI: /ifs-admin/core/settings/diagnostics/
SCRIPT_NAME: /ifs-admin/core/settings/diagnostics/index.php

Is there anything else that would be useful for troubleshooting? Thanks for the help!