I have not done any mods yet. I hope to learn from OP

I don't have one but I think @Undisciplined and @siggy47 do so maybe they can help you out. 

grayruby

bitcoin_Mining

If you have a Bitaxe Gamma, have you tried?

1) Running a y-cable from the header to power 2 fans?
2) Zip tying the second fan to the frame? (basically to cool down the VRM)

Essentially I'm trying to determine if there's enough power for a second fan using the same block (cleaner setup, IMO) and also if there are any vibration issues by doing so.

Thx! 