I created a bug report in the feedback tracker for this but I'm hoping to get eyes on it here.

https://www.reallusion.com/FeedBackTracker/Issue/Convert-to-Game-Base-creates-a-low-quality-texture-bake

The issue is that when I convert my model to Game Base, the UV shell placement is fine and the general UVs are ok (not a fan of the single body UV shell as it limits your texel density) but the textures that are transferred from the original mesh are insanely low quality. I'm not sure what the transfer process is but it looses tons of detail and gains a pixelated look. I've included screens in my but report but will put them here too. This is a comparison from a general instaLOD export with materials merged to a single material VS the game base textures both at 2048. Typo aside, I think it illustrates the issue.



And here is a game base result at 4k. This should be full of detail yet the result is pixelated and blurry. It looks horrible in Unity. The instaLOD export with a smaller UV shell for the face has more detail than the game base version with a much larger UV shell for the face. So something is broken in this process.

Hi DSD_Brian
This is the Bug ,which existed for a while.
Please check your "Max Texture Size" preference setting in Real-time Render Option section.
This bug will make this setting affect your game base convert texture size.
If you want get 4K result, make sure the texture size setting has been above 4K.
hope this will help you.

Getting 4k texture size is not my current issue. My issue is that the resulting texture from converting to game base is extremely low quality. It doesn't have to do with resolution or even texel density but rather the resulting texture quality from whatever method they use to transfer/bake maps from the standard CC3 base.

Alright, I seemed to have misunderstood your point. After upping the resolution of the RTR to 4k, my bakes are now a higher quality. While this is an ok work around, it's a silly bug that I wish they'd fix.