Calling a 3b with pocket pairs oop against regs

That is a leak. It is very difficult to play this spot for example you need to find some very tricky check raises on the flop, find very close calls vs turn barrels or start bluffing them very aggro vs check backs on the flop etc.
So all situations that let you to underrealise the eq compared to gto. Ofcurse the ip player is also not play optimal but in generall it is much easyer to make mistakes as oop then ip so we need to be carefull i would recommend overfolding as long you didnt put in the study for this spot.
A effective way of study would be to look at low pockets in isolation and say wich mistakes is villain doing and is there a way to take advantage of them with my low pockets ?
So for example villain is overfolding to xr significantly then check raising flop becomes +ev with some of our low pockets and also on turns where all the natural draws get there for example you check raise flop and flush get there on the turn villain will have a hard time finding intuitive bluffs in your range so he will autmaticly overfold to a barrel on the turn and your pockets will perform very well in that szenario.
Just a quick example dont just implement this now you need to put in some time looking up villains mistakes and create a plan how you will play with your low pockets.

pure set mining is probably just always bad, unless you're playing against ppl who you know will call way too often
there's the 10-20-30 or preferably 15-25-35 rule too: effective stack needs to be 15x the call you need to make to set mine profitably, 25x for suited connectors and 35x for gapped suited connectors

99-88 are pretty playable post-flop, you want to call and even 4bet them some of the time
77-66 is a bit harder to play, folding is probably fine
55-22 probably just fold to make life easier

Thanks for the info guys, given me lots to think about