I just found out today that Primegrid can run GFN CPU work on ARM 64. I have 16 RPI 4's that I have been running on Einstein because the options have almost dissappeared for Raspberry work.
I have one running a teast on GFN 17 now on all 4 cpu's and estimated tome is only five minutes and is a proof task. Maybe they will only run proof tasks, if so no use running them. Time will tell...
UPDATE I had to increase the amount of disk space for BOINC in preferences but they are all working on GFN 16 now, both main and proof tasks