Tinkerer would have to make literally hundreds of alternate images showing the MC with different physiques/appearances, and tie which ones to show based on the MC's level. There's a lot of questlines you don't have to do right away, don't have to follow up on, or even skip entirely. Mia, the giants, the vampires, Liandra & Luthien, etc.
The alternative is to have more experienced models at certain points in the game while accepting doing some of those side questlines later will show the MC with the "less-experienced" models if you don't do them until later in the game. Not doing Mia's quests until you're Lvl 20+ and getting early-game images of the MC when you do it would be kinda weird in my book. I'd rather have a consistent MC appearance than jumping back and forth with it.
