Jeff,
I think you would be surprised how many and how much greens grow over time if the cleanup pass and collar lines are not monitered and maintained over time.
This is especially easy to do when the greens, collars and surrounds are all cool season (especially when most of it is poa annua). Its harder when the green is cool season and the surrounds are warm season because there is a defined line to keep it under control. And it makes it even easier when the greens are pushup soil and you dont have the clear cut greens edge like you would when you have the sand / soil interface with a sand based green.
Its all due to the maintenance crew being aggressive with mowing up to the edge of the collar on the cleanup pass on a daily basis.
For example, the course I grew up playing as a child is an older Ross with pushup soil greens that consisted of 99% poa annua that matched the 99% poa annua approaches and wide collars that were shrinking over time. All due to the lack of monitering the origanal green edge and the greens mowers being aggressive with the cleanup pass over the years. Those greens edges were reclaimed and and brought in 4 feet in alot of places.
And your right, it also goes the other way, if the greens mowers are always mowing the cleanup slightly inside the edge the green shrinks over time. That 1/8 to a 1/4 inch in or out every day adds up over time, especially if gone without monitering.
From the turf side Im anal about maintaining the edges with everything. Greens, collars, approaches, fairways and tees. Im out there at least once a month with spraypaint repainting edges for the mowers. Youd be surprised how much these lines can move even in a month's time.