I don’t fully get the exp aspect of blue stars yet so this may be a foolish idea but based on the OP perhaps have each BS provide the base exp that would be required to gain it towarda character level?
As I understand it they provide a boost of 10 levels on reincarnation and count as 10 levels when factoring experience gains for levels in that skill? Yet not towards the character level total?
Just ammend that last part? That will remove some of the grind of reincarnation as well, and eventually remove the more negative aspects though, which may be a good thing, although ascension may then need a buff.
I’d need more information on how the system works to suggest something balanced. Anyone able to weigh in?