Oh, so there’s some related topics to this that get close to what I want. Here’s a two button variation that’s a lot simpler (and one I’m willing to settle for if I can’t get this to work)
Here’s an alarm clock with a snooze button
Here’s a thread on using the input_datetime helper within a template to trigger an alarm 24h before within an automation (not as the primary attribute to pull the desired time as a readable input). This is the closest to what I had in mind.