when dilating, often I have a lot of pain around what I suspect are certain scar rings in my neovagina, basically areas where it’s much harder to push past, almost like a sphincter but without control to tighten

I have discovered that after pushing painfully past certain points I can experience painful burning sensation, but if I pull the dilator out, put a horizontal ring of lube on the dilator around the threshold of how deep it goes in, and then put the dilator in, I often manage to get the same depth as was painful before but experience less pain and burning. I think this is twofold, maybe relaxing and re-inserting helps reduce tension, and maybe the lube at the edge helps prevent pain from pushing deeper.