Synapse

Have you tried running in a Wayland session if you have the same issue ? I am not so sure, but I think GPU acceleration is only really working with Firefox in Wayland. Also, check which version of the Nvidia driver you have, maybe there is something newer you can use from the backports repository.

I once made an animated presentation using Inkscape and an add-on I can’t remember the name of. It was epic and blown everyone’s mind. But it was not worth the effort and I have never attempted this again.

You can use 7zip to archive files into a .7z and protect it with a password. 7zip is cross-platform, it’s available for Windows, Mac and Linux.

Edit: sorry, I see you have already evaluated this option. I don’t know another method that would me more transparent.

TIL the term glowie comes from Terry Davis the creator of TempleOS.