Well  if it is a gpu rig  and the os has a unique  number

the mobo has a unique serial number


and the cpu has a unique serial number

link the three as a set.  and you have a unique rig .   



and I am not looking to exclude asics if you want to use them  buy the super size  os with less restrictions but more costly.

Variations on this have to work and not exclude any one.  but hinder big ass mining with large asic rigs.

The  os  could be a 512 bit encrypted code  different for each one

The server on the pool reads it and knows it is a small rig or a big rig.

Asics will work  but at a higher cost due to the big size os .

and the os is restricted by size.  There must be identifier that is anonymous and unqiue.