I guess we are all completionists, as much as it's possible to be, depending mostly on the extent of our collecting parameters.
When coming to the end of a 'basic' run of Freeman pennies, I'm guessing there'd likely be a temptation to expand it further into the more recently published micro-varieties? Equally, one might opt for the pleasure of closing a lid on something, and beginning instead a new Davies run of shillings?
It's human nature, particular the nature of males, to want orderly boxes, for everything, so a micro-varietal penny collector is no less diseased (well, maybe, lol) than the collector who 'closes the lid' on a simpler Type Set, only to immediately open the lid on a new box.
We just keep going on, for as long as we can suffer the tension that an open-lid box delivers upon our delicate little male brains (and the delicate little brains of some very strange females too, of course ).