Seems to me that a monthly flip flop or not flip flop based on the hash of last block of the month. Would be a P.I.T.A. for all miners
but
GPU--- Bad
FPGA-- Worse
Asic---- Worst
You need 2 asic chips one for progpow and one for CNv2 so it would hurt asics 2x
You need to flash your fpga and would hurt it somewhat as fpga flashing is not super easy
You need to switch from one program to another on your gpus takes under 1 minute per gpu
My developing skills are small but I am a good idea guy.
Anything to hurt asics should be good.
And this idea could be expanded.
If you have 4 hard algos and hash tx for a block is hexi- decimal
4 numbers for algo 1
4 numbers for algo 2
4 numbers for algo 3
4 numbers for algo 4
that would really hurt asic mining big time as you need 4 separate chips one for each algo