If it is going to implement, then it should be carefully set what iL
if I am going to set iL for 3.0 leveling dung,
I would say 90-100 up to The Aery
Then 110 to The Vault, and may be 120 for ARF
full set of ironwork can be easily obtain with 2.0 era contents
and 100-120 is pretty much enough to go through all 3.0 leveling dungeon
unlike loot in dun which is pretty much luck or RNG, if RNGesus troll you
you could end up like my AST who have to wear Ironwork upper till I reach the Vault
as for future 4.0 leveling, if iL is going to implement, i think no higher than iL230 should be set