Basically you need to set the RPM with the throttle and then the pitch with the pitch knob. There will be basic numbers for take off/climb and whilst in the cruise. You need to monitor it during the climb as it will need adjustment as altitude changes.??????
Surely you mean set the manifold pressure with the power lever (throttle) and the rpm with the prop lever (what the hell is a pitch knob?)
I've only flown a DV20 Katana and can't speak for the DA20, but IIRC the DV20 has a Hoffman prop. It had a seperate throttle and prop control.
It was a long time ago, but IIRC the power (manifold pressure) was not reduced in the climb, but the rpm was reduced. This is a little unusual to those of us brought up on Pipers, but nonetheless was the POH procedure.
To answer your question, no it will not greatly add to your workload, but you'll need an hour or two to get the new procedure into memory.
Nice aeroplane.