Short update regarding conda environments
While there has been some progress getting PsychoPy to run natively on M1, this solution seems to require a fair amount of hacking around, and not everything works. Continuing to run PsychoPy through Rosetta still seems to be the easiest solution as of now (though I cannot comment on performance for running real experiments; my interest here is for teaching and development).
However, short tip for anyone trying to install PsychoPy through a conda environment on an M1 mac: To run via Rosetta, you will need to make sure you’re using an x86_64 version of conda (e.g. here) in a terminal configured to run Rosetta. You can do this by following these instructions, duplicating your Terminal application, renaming, then changing the renamed terminal to run via Rosetta. You can check by typing arch, which should return i386, not arm64.
Then you can install PsychoPy via the relevant environment file.