I have a suspicion that the bus schedule mgrs in OP do something similar which may explain why some ot the NYCT bus lines have such strange headways especially overnight. Unlike rapid transit, bus operators report to a depot and either pull buses out or deadhead to a designated relief point along the route which in most cases is not the actual terminal of the route. On some lines where there is no convenient point to relieve the operator or his lunch (or “swing” as NYCT personnel call it) the operator scheduled for his lunch pulls into the depot from the terminal and a new operator pulls out to cover the trip. The same is done at the end of the operator’s run. If there is no convenient relief point then the finishing operator pulls in and a new operator pulls out. On most rapid transit lines at least on the NYCTA, crews report to the terminal and pick up their trains there and are relieved at the same terminal for lunch although sometimes the crews may get their lunch at the opposite terminal depending on how the work program is set up. The only crews who report to or clear at a yard are those who have to prepare and put a train in for service and/or lay a train up. I have noticed on other transit systems such as WMATA and BART that did not have a tradition of rapid transit like NYC prepare their work programs like bus work programs and have their operators report at yard facilities and make reliefs enroute. Overnight if it’s time to relieve a crew for lunch, in rapid transit, a new crew is merely called out to cover the trip and a new run is created. In surface when it is time to relieve an operator for lunch, no new operator is called out but the operators next trip departs after the lunch period is over, thus making an uneven headway.
I have seen bus operators taking a break while I was waiting for the bus to start its run, and it does result in scheduling gaps. While understandable, it is quite frustrating, just as was waiting for the letter carrier to give us our mail while he was parked across the street from our house eating lunch back in the days when I worked from home and was desperately waiting for what little checks I would get so I could deposit them by 3 PM.