That would be a cool feature for sure. I think it would be hard to add though, as it would probably require a lot of back-end work to add the required pieces. Automations might easier if they can do a trigger > delay > send message flow, that might be a way to do something at least similar without rebuilding the whole messaging system.
The only workaround I can think of is pushing it to a third party, which adds more complexity than your current workflow has.
For what it's worth, if someone replied at an odd hour, I don't think they'd expect a reply from you outside of normal hours. Not trying to invalidate the concern; it's just not something I'd thought about before now. You make a good point.
