I would still suggest using the breakout board and buy or make PCI-E power cables for it.
The thing is that the machines are here, delivery times are around 2 weeks, that's a loss of money.
If moding the server board is safe for the miners, I would use them, if power output (2.5A max per endpoint) is too little and will hurt performance,
I can always sell those to PPL with similar miners that consume less power on ebay once replacement arrives.
What do you reckon?
Thanks,
O.
P.S
Where do you mine?
Do you mine on a standard pool? merge mining? multi mining?
I came up with a merge+multi mining pool with a friend, and it was much more profitable than Prohashing for us with our 2 old miners (Innosilicon A2 and one tube of an A4).