As the only mod ive seen that manipulates learning in this kind of way im starting here:
Can you/is it possible to make a mod that lets children have (mental) growth moments based on chronological age if their aging speed is 0%?
And eventualy move them from learning to recreation aswell?

Background:
I had a similar idea to https://steamhost.cn/steamcommunity_com/sharedfiles/filedetails/?id=2929374934
and experimented with https://steamhost.cn/steamcommunity_com/sharedfiles/filedetails/?id=2926556467
to see how it would fare.

A quest came in about a runaway child chased by tribals.
She spawned with age 5(58) as a Half-Vampire.
In terms of Story this has amazing potential but because the game doesnt give a ♥♥♥♥
she was spawned in with no traits, no skills and no passions and will eventualy forever hang at growth stage 8.