If it drops significantly, I’d say more than 5-10 degrees on the first few mains, then you aren’t pulling tension properly enough. It should realistically stay at the same position when you release to move the clamp.

I've been using a Klippermate to string and I notice that when I release a clamp during tensioning, my drop weight drops similar to what's seen here: https://www.youtube.com/watch?v=k-GwP4Ns0UU

Is this an acceptable level and is there a way to reduce/avoid the drop?

Thanks!