Yes a midi clock that has jitter will affect the midi timing from the Digitakt midi out for sure.
Overbridge version 1 had a sync feature and I don’t know if this was based upon audio pulses being sent from the overbridge plug-in to the Elektron hardware but I suspect was/is.
Overbridge 2 might have something similar, we just have to wait and see what the future brings.
But sample exact notes on the grid is probably not healthy to strive for. Can be quite expensive to go all in trying to get the same accuracy as you get in a software DAW with plug-ins.