This is certainly an option for restricting long rests, but it has similar problems as other suggestions. [various questions]
Your questions are indicating that you didn't read that thread, the one I linked.
I read the thread when it was originally published, and I skimmed it to refresh myself. You provide some investigation of how it currently works, and then provide suggestions as to how it could work better. Your suggestions are 1.) x real time = y game time, or 2.) progress time based on events.
The rest of the thread discusses various implementations, issues, and benefits of your suggestions, which is essentially what I say in my post: these points need to be considered. And tbf most of the discussion in that thread was about making time passage make the most logical sense and immersive (which is important!), rather than explicitly balancing it with D&D's long rest system-encounter and class design. Am I incorrect?
What happens if you're out of resources but only 16 hours of in-game time have passed? Do you just have to afk until enough time has passed? Or can you speed up time to instantly wait 8 more hours and then rest? If the latter, how is this different from the current system of unlimited long rests? And in either case, are there any consequences for doing so?
If 16 hours passed it means that you already can rest, you don't need to wait 24 hours BETWEEN the long rests. It's just 1 long rest per 24 hours. And the consequences are pretty obvious in how it's phrased in the book: you may rest right after the previous rest, but if it's not a new day you do not benefit from it (no healing, no spellslots).
In that same thread I already wrote all those options like deleting that clock and make the player push the time through actions (ideal in my eyes). But I also think we should be open to compromises here and maybe give Larian more ideas to think about.
This is what I meant, but admittedly I phrased it poorly. I was counting time from the initiation of the previous long rest: 8 hours rest + ~4 hours adventuring + ~4 hours eating = you still need 8 more hours until you can get the benefit of a long rest. If you're out of resources, how do you pass that time? Just afk or can you press a button to skip 4 hours or other?
You suggest pushing the time through actions. But what happens if you've exhausted all the non-combat actions you can take (dialogue, exploring new locations, etc) and only have combat opportunities left, but you have no resources? This risks soft-locking the game.
Edit: I'm not necessarily
categorically disagreeing with your suggestion to limit things by the game clock. I think it's possible that such an implementation could work, and it'd also provide nice immersion! I'm just trying to address any potential issues so that we can arrive on the best solution, because you know that some people will come in here and use any issues to say "this possible issue is bad and thus long rest restrictions are bad in entirety."