To my knowledge, covenants would enable confirmed transactions to include “can’t spend” conditions on outputs (such as block height), but thats not quite what I’m after.
I want to sign a transaction sends to regular addresses, but includes a stipulation that the whole TX is only valid if included before some height.
I don't think this exists. The issue I am thinking is that even if you send a transaction today, it might get confirmed next week... Heck it might get confirmed in a couple of months.
I've not thought too hard about this, but that might be the reason why it isn't possible.
Agreed that the time-to-confirm is unbounded. Nevertheless, I believe it’s within the realm of possibility for there to be such a feature. I’m fairly certain such a feature does not yet exist (and I’m aware of no proposals).
