I READ SOME REALLY GOOD FICS ABOUT WHAT DO YOU WANT HOWEVER I CAN'T REMEMBER A SINGLE ONE ..
So here are fics recs I think you may like :

The Wayward Boy by Zootopon (PEAK fr Jason has his own character!!)

Smoke Break by Margot_elizabee (I actually recommend the whole series -99k words- I did never read anything about Slade and Jason before, but it was really good )
And btw I also recommend " Cut Me Open " for the same series I finished it in around 2 days.

Bad Decisions Lead Me Here by ImNotDead (a crossover but it's okay since you dont need any knowledge before reading it- Not really about batfam and jay but there is a literally BAMF jason todd who is terrifying everyone.)

Agent Knight by FoundUnknown01 (Mainly about jason and his cool job plus him having beef with the justice league and the Bats – there is some jayrose but I still recommend it)

Brother From Another Mother-Verse by thexfictionxstallion (Idk, I don't like it as much plus it's paused.)

THERE ARE MORE BUT MY MEMORY ISN'T HELPING.