Yes - it seems to work just the same for the Powerstore Ribbon & Lightbox as it does for the other one.
For the Ribbon + Lightbox for PowerStore,
Open your /PowerGallery/galleries/ribbon_lightbox_powerstore/index.php file and find line 14:
$gallery = get_gallery(get_mediarss_url('gallery=' . $pg_id . '&thumb=62c&full=782p'));
and change the '62' to '92':
$gallery = get_gallery(get_mediarss_url('gallery=' . $pg_id . '&thumb=92c&full=782p'));
And at the end of the block of code at line 60, change width="62" height="62" to width="92" height="92"
Upload that page. You will also need to make adjustments to the stylesheet (ribbon_lightbox_powerstore/css/common.css) similar to those shown earlier for the other gallery.
Hope this helps,