I don't know whose briefing Trump on Ukraine, but his proposals last I heard didn't actually consider any of the reasons the war happened in the first place...ergo, they are unlikely to be even considered by Moscow.

Can't recall who said it but the casus beli was all about whether Russia's say in Ukraine joining NATO or not would be decided by means of negotiation or war: unfortunately the west and Ukraine chose war.
-It's not a decision that can be backtracked down the tracks with well over a million dead or severely injured.

After spending $5 billion to destabilise Ukraine and organise a bloody coup, even more to train the biggest army in western Europe (did anyone ask why one of the poorest nations in europe needed the biggest army?) incorporating of course its NAZI coup militants...in NATO tactics, after loading the place with multiple billions in tanks, armoured cars, planes, artillery, missiles, shells...
but still to be losing...

-Trumps best shot to keep his "legacy" clean would be to walk away from the mess and hand it over to Europe and the Brits who can carry on with the failure or not as they wish or indeed can afford, but who will take the blame non the less for its unravelling.
-If he has any real business nous, that's what he will do.