I agree that right now a big problem is that both Fort Joy Prison (and according to some people, the island as a whole) do not have sufficient XP buffers to allow players to miss some of the optional XP gains. The prison is especially bad because you have very little room for getting to level 3, and you can end up being forced to do things in a very specific order because you can only handle certain situations.
I experienced this myself. I failed to talk to Elohdi and intervene when first entering prison, and when I got back, she was dead. I missed that XP. I also was roleplaying as a lizard mage, and so when I talked to the playing kid in the grotto, I didn't choose the "playful" response, so the kid never played hide-and-seek or told me about the secret area in the grotto. If I was a first-time player doing this without knowledge, I wouldn't know about those, so I pretended that I didn't know what I missed.
Because of that, I was level 1, and I only had one quest I could do, which was to find Griff's fruit and turn Stingtail over to Griff, because I couldn't win any of those fights at level 1.
(In any case, I also didn't have enough Strength (12+) to pull the spear from Withermoor, which meant he didn't reveal a secret way into the prison.)
However, I do not think that respawning enemies is the only way to solve that, instead I'd prefer if new areas, more low-level enemies, and more low-level quests are added instead.
