Personally, I stop doing detailed (i.e. frame by frame) inspections in late July/ early August as even the quietest bee can get a little ansi when the flow stops. Also by that point QC are not likely to be swarm cells but superceedure cells, in which case the bees proably know best and depending on your personal perspective should just be left to get on with it.
After Mid August I only worry about those conlonies I know to be weak or I have issues with. I also, due to time constraints, don't take my honey off until August bank holiday, and and therefore don't start my varroa treatment till then. This means that I'm still visiting the bees and opening the colonies till mid/late September so, assuming I know what I'm doing, can spot potential problems.
Not using frame feeders, either using a rapid feeder or miller feeder, does make life slightly easier when feeding if they're ansi, but in the case of the latter taking the feeder off if you replace the crownboard with the feeder can be interesting.
At the end of the day, the point at which you stop doing detailed inspections is your own decision. I and others can only offer perspectives.