Sometimes, yes. Although I have tried hard to standardise the couplings, sometimes the distance between the buffers and the loops varies slightly which means the gap between the buffers is a bit narrow, which means it's harder to get the uncoupler down between them. When I've fitted all the couplings (still got about a dozen more items of stock to refit), I might check them all again and make a few adjustments. I might have to replace some hooks with slightly longer ones to make uncoupling a bit easier. Otherwise, they are no more fiddly than standard LGB plastic couplings to uncouple.
Rik