I have two broodies in a 6' x 6' partition of one of my coops. I moved them there, from another coop. Water and food are probably less than three feet from the nests. This section works out best, as its semi dark and I can close it off from the rest of the flock, without disrupting the daily routine of anyone (human, or, chicken). There are only two nests in the mini coop and in the past I've noted the hens changing nests through the incubation process. No big deal, as they were given eggs at the same time and will got to separate tractors, when the hatch is done. When I only have one hen in there, I block off the unused nest.Cheapest way for me has been the time lapse option but you might also setup a game camera to record movement around nest. You will then get a handle on how often eggs are rolled. I have a hen coming off nest in garage with an unknown number of chicks. On warm days she spent more time off nest than when it was cold. Having feed easy to get to also shortened feeding time. In her setting she actually walked past feed and water to defecate and that was often done in elevated locations.
Had I read your post, before they started, I would have done a little experimenting.
I'm laid up at home, after a fairly complicated surgery and will be here for three more months. I think I'll try moving another broody, should one come along and the timing is right. This next time (if there is one), I'll set up some indicators, to see what the patterns of the chickens actually are, after I force them into their new nest. It may be something as simple as a piece of tape they have to break, to exit the nest box. This should be good therapy for my recovery and get me out of the house for some short walks. Not as productive as being back to work, but better than watching TV and surfing the internet.
Probably the only reason I've been on here lately is because I've had so much time at home doing nothing.