Like I said someone going to overclock them 10-20%, I'd just go with one per each psu

main reason I didn't go with it is I run the rear fan at 100% off the psu and can't do that with these bitmain psu's that I am aware of

If you haven't noticed the L3+ fan controller is buggy. I happened to catch them overheating while both fan rpms showing zero, sure they reset but they reset into the same buggy state -- over & over until the board burns up -- saw it happen a couple times, once on auto fan control another  time on 75% -- so you can have your cheap bitmain psu's feeding their buggy bitmain fan controller.

oh by time the board actually shuts down & resets the temp is actually over 120c, so  the 80c cutoff doesn't do much, it's not an instantaneous shut down and it's not a failsafe

a few of those cycles and your board will be shot