Check the manual but I think that is too much. 3% or 1.8Hz drop with a full 100% step load from 0% to 100% is a typical spec and not always easy to achieve, I might add. I would settle for 4%. That set is around 6%. I don't know how these 002A's are set up but most of the mil spec non civilian units i have come across have some adjustments to tighten it up. You will need a known combination of loads to get to 5kw. It does not make a difference if it is gradually loaded or step loaded the final result will be the same. I have had to totally reset lots of the smaller units going step by step through the book. It seems many like to turn a screw here or there to solve one particular problem then the whole system gets out of whack. amazing how good they can run with a full tune up.
For those that have asteady load a speed adjustment once settled in is often good enough.
BTW whats with the gages fluttering and near off scale? Nice unit, though. I like the ones on the trailers, very versitile.