I stream and my computer has some nice specs 64gb DDR4 ram, a intel i5-14600KF and a Nvidia GeForce RTX 4060. It seems to run my Vtuber model perfectly fine with like 5 other apps open but as soon as I open the software and just one game it kills my entire PC!! Does anyone know a fix? 

Also for the creator (idk how hard this is) But maybe making 2 versions of the application could be good, like One that uses OpenGL for tyhe older hardware and one that uses Vulkan for the people who want to use it on newer hardware to have a broader range of people being able to use it.  Just an idea :)

The application isn't particularly optimized, and the developer acknowledges this in the github notes themselves.

What resolution are your source images? The software does a lot of caching that could be significantly optimized, and I've noticed MASSIVE memory usage when I run it with a fairly high resolution model that has dozens of images.

Reducing the image size down to what you need will help with memory usage in the meantime.