I get your point, and it's interesting, but I think one major flaw is that you are assuming that this will put Ukraine in US favor. I don't trust this administration a bit, and I don't think willingness to compromise or the appearance of being deserving will change our fearless leader's disastrous policy. It might help to reveal to those not yet willing to acknowledge it, how much he is in the Russian bag, but otherwise, I doubt it will have much of the effect you hope for.
I thought I posted this above but it seems as usual I forgot to push the button.
Others have since responded, and I do also think it a mistake to pronounce a willingness to give up territory, insincere or not. Not only does it send the message that much of the war was unnecessary, but it risks that the Russians will take the offer. After all, it's Russia. They can easily take the offer, claim a settlement, and then invent a reason for breaking the deal and invading again.
I think you trust both Russia and the US more than is prudent.