I'd have to agree with harperfan7 here: these smoke bombs are a little too good.
The problem really comes from the fact that they make
everyone of the map
instantly lose your track (irregardless of line of sight, etc).
It would make much more sense if they worked largely the same (i.e. allow you to enter stealth, converting AP to MP), but only provided an equivalent of one extra turn worth of staying out of sight.
Right now they effectively provide an equivalent of 4(!!!) turns of staying out of sight.
It's as OP as well-placed flashbang imo.
Except it's often technically impossible to incapacitate all enemies with one flashbang in most combats where you'd what to use these smoke bombs (too many enemies and/or some are immune to FB). Not to mention the fact that flashbangs are intrinsically unreliable (miss chance and resist chance) even when they have theoretical chance to work.
P. S.
you get them almost at end-game
Eh..?
You can get access to oculus practically as soon as you finish depot A.
That's early mid-game.