Hi, sorry, the non-free is a very Manjaro-specific thing.
TLDR: They removed a lot of proprietary video codecs from Mesa, which means that Manjaro's Mesa tends to lag behind the Arch repo. By using nonfree, the Mesa installation is pulled and compiled straight from Arch.
So yes, I'm using RADV through Mesa 24.1.1 instead of version 23.x (which is where Manjaro is still at). I wanted to be on a newer version since 24.x packed in a lot of 7000XT improvements.
Out of curiosity, have you tried AW2 with your 7800XT? How does it run for you?
I'd done that a few days ago, but you're right, not specifically to these suggestions. I tried the export VKD3D_DISABLE_EXTENSIONS=VK_EXT_mesh_shader VKD3D_FEATURE_LEVEL=12_0 VKD3D_SHADER_MODEL=6_5 %command% and variations of it. It reduced performance significantly, so would not suggest people on more recent Mesa versions try this anymore. When I looked into it, it seemed to mainly be in place for Mesa 22.x which was still lacking mesh shader support.