In my experience, the real problem with any support scheme is that the decision makers don't have enough skin in the game. It's easy to deprioritize tech debt and bug fixing when you aren't facing 3am pages.

The obvious solution to this is a distributed team. There can still be some holes (e.g. Jan 1 is, afaik, pretty universally celebrated), but having worked at companies that had a team in the US, Europe and Asia was...really nice with respect to this.