You say that with such invective. A wait of 5 minutes is considered good in almost any part of the world, particularly if outside of rush hour.
I have very rarely, if ever, experienced a 4 minute long crew change.
Crews are supposed to be at the ready, correctly positioned on platform to relieve the incoming crew, in my experience, the average delay is 90 seconds or less.
I hasten to add that I'm completely unclear on the overtime comment. Crew changeovers are a regular part of subway operation, people's workday has to end at some point.
Changeovers are done @ Coxwell Station on Line 2, not sure where they are based on Line 1 these days.
They are a routine part of scheduling in most cases.