When the liners pack out, does re-heating...
When the liners pack out, does re-heating and re-fitting work to "restore" them?
The second molding will never be as good as good as the first. If you messed up the first mold, you can redo it about three or four times without compromising the liner. If the liners are packed out, though, they won't be revived to their original pristine state. If you're looking to get a snugger fit in your boot, though, it wouldn't hurt the liners, but they wouldn't fluff up or thicken at all.
Can you purchase replacement liners?