Can File Size be Modified?

Sure, if you look for the following line in ht-gallery-proofing.php

'max_file_size' => wp_max_upload_size() . 'b',

You can change that to whatever you want, or if you want to change it across your WordPress installation, be sure to look at this page.

[ Signature moderated. ]

Apologies, I meant hero-gallery-manager.php. Hope that helps.