I've suggested this on the other exp-related thread, but I'll repeat it here. Larian should allow players to level past the cap (presumably of 12) by one or both of the following:
1.) multi-classing. The Level 12 cap is class-based, so after reaching 12 in a single class you can always begin taking levels in other classes.
2.) feats. Level "13" fighter would be your level 12 Fighter plus appropriate HP Increase, Applicable Proficiency Bonus Increase, and you get a Feat to compensate for the lack of implemented actual level 13+ Fighter Abilities. Spellcasters would get new spell slots but no higher level spells, along with the stuff mentioned previously.
That would be a good idea. Many builds are optimized by taking 1-2 levels in a different class and this way you wouldn't be penalized overall for having to dip into another class.
It will not be a good experience for people to hit max level well before the end and not be able to improve their characters.