Goal keepers and sin bins.

[afronaut81]

Do all leagues have rolling subs? If no then this is even trickier.

Probably a majority of the Leagues that have mandatory Sin bins.
It's possible that some don't as the number and type of subs is a Competition rule in the SCOR (FA's Standard Code of Rules) so is subject to Leagues adopting it at their AGM.

 

[Peter Grove]

Do all leagues have rolling subs? If no then this is even trickier.

Surely that should be, "Do all leagues with sin bins have rolling subs?" According to @RustyRef 's post, no they don't.

Whereas at supply league, where sin bins operate and most teams will have a backup keeper on the bench [...] there are no repeated subs