Perch Runway rewrite block rule conflict with page

I have converted my site to Perch Runway and have added the Runway rewrite block in my .htaccess file like this

RewriteCond %{REQUEST_URI} !^/perch
    RewriteCond %{REQUEST_FILENAME} !-f
    RewriteCond %{REQUEST_FILENAME} !-d
    RewriteRule .* /perch/core/runway/start.php [L] 

I also have a page in my site called /perch-cms-development.php but when I configure this in Runway in page options with a page path of /perch-cms-development I get a 404 error when viewing the page. It looks like the first RewriteCond in the .htaccess file means that any page beginning with /perch will always have this problem. Is that correct?

I don't want to rename the page if at all possible because of Google rankings. What's the best way round this?