Hm, that reminds me of boring edgelord takes I've seen on how Anakin never really changed, he just switched loyalties again but would act in the same ways, or how even very evil people can have it in them to care about their own child/loved ones without it being redemptive ergo it's not a redemption arc, or he never really regretted anything he did, or blah blah blah. I always find those kinds of takes on him both smug and stunningly oblivious to what is a very straightforward redemption arc IMO. (I love it, but subtle it ain't.) He was redeemed, his last lines clearly marked a change in his sense of himself, he got a glowy blue ghost on good terms with Obi-Wan again, he smiled at Luke at the Rebellion victory ceremony—this is all very obvious stuff. I think that his conduct would clearly have been different, had he lived.

Now, I don't see him grovelling or being suddenly accommodating to everyone. It seems likely to me that he and Luke would nope out to recover / figure out where to go from there. But he's not what he was.

I think it's important to consider that he turns from the Dark Side of the Force, which manifestly screws with people's minds. I don't think Anakin would or could have ever become Vader if he weren't sensitive to the Force w/ all that entails, and I don't think he could continue on his path without continuing to accept the Dark Side, either. So once he's turned back, his state of mind and inclinations would be different from his as Vader (as indeed they seem to be in his last moments). I think this is an element that gets really overlooked wrt Force-sensitives generally, but would strongly affect his personality and behaviour if he'd lived.