oh! and as an afterthought: user definable dummy zones might also be a solution – allow users to define one or more dummy/virtual zones and assign them a zone number either smaller than 1 (starting with 0 and then -1, -2 etc) or larger than 72 to place them at beginning or end of a program ( or even a decimal to place between real zones? i.e. dummy zone 2.5 to run between real zones 2 and 3).
Might be useful to research the user base for advanced and delayed master start/stop and zone re-ordering. Any way to figure out how many users on a well pump for instance? Because if only a handful of users would benefit too advanced a solution would only needlessly complicate UI for most (regular) users.