I tested the firmware for 24 hours, Diffa# calculator showed 1.35%.
Poole took 15.4TH/s from 15.73TH/s, which is about 1.7%.
These figures do not exceed the declared Dev fee of 1.8%.
Electricity consumption 1480W at an ambient temperature of -2°C

The firmware takes into account the switching time between the pool so that at the output you get an honest 1.8% Dev fee