I don't see Putin agreeing to it.

If he does, great. It's not a just outcome, but it at least ends the killing and forestalls future killing.

It does have the advantage (for Putin) of Ukraine not actually joining NATO. But Article 5 is part that he cares about most. It's the one that curtails his expansionism.

So... if Trump can get Putin to agree to that, that's fantastic. It would be a painful for both sides, the only kind of compromise that has any hope of being agreed to. But Putin has a history of letting such proposals hang in the air before rejecting them, and I'm afraid we'll see that again.