Collections - sort by category, sort by multiple items

Is there a way to sort a collection based on a category (rather than a text field)? It doesn't seem to be working. I guess you'd need to specify which field of the category you're wanting to sort by?

Here's my template:

<perch:before>
<table>
    <thead>
        <tr>
            <th>
                Parish
            </th>
            <th>
                Borough
            </th>
            <th>
                Project
            </th>
            <th>
                Activity type
            </th>
            <th>
                Area of concern
            </th>
        </tr>
    </thead>
    <tbody>
</perch:before>
    <perch:if different="area">
    <tr>
        <th>
            <perch:categories id="area" set="areas-geographical" label="Area" required="true"><perch:category id="catTitle" /></perch:categories>
        </th>
    </tr>
    </perch:if>
    <tr>
        <td><perch:content id="parish_name" type="text" label="Parish Name" title="true" /></td>
        <td><perch:categories id="borough" set="boroughs" label="Borough" required="true"><perch:category id="catTitle" /></perch:categories></td>
        <td><perch:content id="description" type="text" label="Description/Project name" title="true"  /></td>
        <td><perch:categories id="activity_type" set="activity-type" label="Activity Type" required="true"><perch:category id="catTitle" /></perch:categories></td>
        <td><perch:categories id="area_of_concern" set="area-of-concern" label="Area of concern" required="true"><perch:category id="catTitle" /></perch:categories></td>
    </tr>
<perch:after>
    </tbody>
</table>
</perch:after>

And here's my perch_collection tag:

            <?php
                perch_collection('Projects', [
                    'template'   =>'projects_table.html',
                    'sort'       =>'parish_name',
                    'sort-order' =>'ASC',
                    'filter' => 'status',
                    'match' => 'neq',
                    'value' => 'archived'
                ]); 
            ?>

I guess the syntax if I wanted to sort by the title of the area category would be

'sort' => 'area.catTitle'?

Also, is there a way to sort on multiple items (similar to the way you can filter on multiple items).

I guess the syntax would go something like:

            <?php
                perch_collection('Projects', array(
                    'template'   =>'projects_table.html',
                    'sort'       =>array(
                        array(
                            'sort' => 'parish_name',
                            'sort-order' => 'ASC'
                        ),
                        array(
                            'sort' => 'description',
                            'sort-order' => 'ASC',
                            'sort-type' => 'numeric'

                        ),
                    ),
                    'sort-order' =>'ASC',
                    'filter' => 'status',
                    'match' => 'neq',
                    'value' => 'archived'
                )); 
            ?>

Both of those things would be helpful on this project - not sure how easy they are, but would think that being able to sort by more than one field could be useful for a number of people.