The current version of neXt (1.674) appears to run fine on the new Apple Silicon based MacBook Pro, despite running in Intel-emulation mode using Rosetta. By 'running fine', I mean a fluid 60 FPS in the MacBook Pro's native full-screen resolution (2560x1600 pixels) at the 'Fantastic' quality graphics settings! For most sceneries, you can crank all of neXt's graphics settings up to the max - shadows, nitro-smoke, dust, etc. - without adversely affecting the frame rate.
Having upgraded from a late-2012 i7-Mac mini with its integrated Intel HD 4000 graphics, I must say this is refreshing ;-) Note that ye olde Mac mini was no slouch either: It was able to run neXt in full-HD resolution (1920x1080) at 60 FPS. But in order to maintain a jitter-free frame-rate you had to disable shadows and use at most anti-aliasing @ 2x multisampling.
Still, I eagerly await a native Apple Silicon version of neXt, as the Rosetta Intel-emulation layer won't be available forever.
Yes, Apple did a fantastic job with their own CPU/GPU. I am impressed too. To be native I need to upgrade to newer Unity3D libraries. This is not trivial as I will lose all of my shader programs. I developed the graphic shaders by myself to make this simulator as fast as it is. Of course, I'll upgrade to the new libraries in a few months, but not now.