Replying to Remolding liners and new footbeds

So my problem is with my 28.5 il Moro t from last year. I am 6'4" 170 and like the way they feel it's just when they warm up my foot is moving a bit. Everyone would tell me to try a smaller boot but I don't want to give up on these just yet. The length since my foot is weird (narrow but long) so the 28 feels ok. The problem with a smaller boot is that the cuff isn't the same height as the 28 so the support bothers me. I bought these boots used so the liners that were in were molded to someone else. My question is mainly would heat molding these liners to my foot make these snug? And would a new insole help make it tighter as well? Thanks guys