To add the variety of curiosities that people study. Somekind of system should be added to reduce the lp that you gain from curiosities, if you study the same thing over and over.
Something like satiations, but for curiosities.
You would have to study variety of things to maintain 100% lp gain from curios.
This would also bring a meaning to forageable curiosities.
There could be two main groups, crafted curiosities and foraged ones. So you would have to study BOTH to maintain maximum efficieny on lp gain. Thus you would have to sometimes go forage for curios to maintain the variety, even if you could craft better ones.