Heel lift sucks so no matter how comfortable its gonna be hard to be happy with them. Maybe go to a boot fitter and get them to help you out with heel lift issue? If it's an issue due to lacing bottom half of boot i'm not sure what they could do though.
Have you had em for a while?
My Vans are coming up on 3 seasons and have packed out a bit much now, the liner is kinda gone hard and its difficult to get lace tension just right... must nearly be ready to get something else