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.
Not seeing what's painful for russia in this plan. They basically get new territory, a weaker Ukraine, lose all sanctions, back in G8, complete amnesty for war crimes. It's a win for them. This was likely written by them.
If Putin actually cared about NATO encroachment, he wouldn't have launched the invasion in the first place.
And "his approval is done deal"... yeah Putin will try to set the stage to demoralize Ukraine and by making them sign a humiliating deal, and then find problems with it, not sign it and make more demands about the root causes of the war not being addressed etc. The deal was that Ukraine would have to sign it first, not that they sign it at the same time with Russia. Putin will never agree to that. Nothing is a done deal with him.
And also, if Ukraine does not accept such a humiliating deal, Trumpt might pull US support to Ukraine, which means Russia can effectively continue this on the battlefield.
This is a good play from Putin, he basicly cannot lose either way. Classic.