Just tried your miner with 2x Sapphire RX550 2G Pulse, stock settings.
Here goes the result:
Hash Rates: GPU1 318H/s. GPU2 318H/s.
Current Overall Hashrate of 636H/s.
Record: 652 H/s.
Runtime: 2 Minutes and 47 Seconds.
But the hashrate is the same as SGMiner-GM 5.5.5, which do not include a devfee and it is open-source.
GPU 1: 69.0C 1729RPM | 313.2/ 338.5h/s | R: 0.0% HW:0 WU:0.000/m rI:280
GPU 2: 67.0C 1224RPM | 313.4/ 338.5h/s | R: 0.0% HW:0 WU:4.730/m rI:280
(ambient temperature 22C)
P.S. Wolf0 is around here and I think he is angry if someone use his code and set a devfee.