Yes, I just released 2.5.0 of the Add-On. It should offer a custom capability for
With a plugin like User Role Editor, you can add that capability to Authors and Contributors and Subscribers (or any role desired).
Then when loading the form as a user with such a role, you should be able to upload images.
All without full access to the Media Library.
Please be aware that you want strict moderation on these images in the Media Library. That is what the notifications are for.
Also, if users are not logged in, you cannot assign any capability to them. Only with a user account does someone have a role with capabilities.
By the way, there will be an admin notice about upgrading the main plugin. That should be fine, I will release that later, so people can first update the add-on.