idk what it is specifically...
whether it's the DC and the scheme, or the DL coach, the 49ers always seem to maximise their EDGE/DE rush whether they're rushing outside or inside
samson ebukam's been great since he joined them, drake jackson looks flashy as hell as a rookie (really liked him a lot in the draft) but last year they turned arden key's career around too
obviously it helps that they've invested a ton of draft picks into their DL in recent history including some very high picks (nick bosa, arik armstead, deforest buckner - who's now a colt, javon kinlaw, solomon thomas - who busted as the 3rd overall pick) and now drake jackson too