As things stand, remember that in-game vision above 40 can stand for either TI or radar (typically GSR for Ground Surveillance Radar). Both are considered identical for game purposes, and behave the same way with obscurants.
Generally units with radar within the game scope are recon/surveillance units, like the newly added PRP-4M and SNAR-10.
Few combat units use radar vision, Marcello mentioned the MT-12R (I think), there should be the Khrisantema launcher, and of course some combat helos like the AH-64D and Mi-28N.
I repeat, that these units have a ground-targeting radar or TI doesn't change a thing in the way they handle smoke.
For modeling purposes, I guess you could consider that for equal technology levels, a GSR would have 150% the range of a TI sight (e.g. 60 against 40 for most units), but that's a wild guess from me only.
I agree, there is no proper way to model
bad TI, like some 70s sensors that could certainly see through smoke but couldn't pick out a tank clearly beyond 1km, the same way that you can't model bad laser rangefinders (the kind that are easier to use but less accurate than coincidence ones).
For now, I can live without them as far as I'm concerned.
Regrding lasers and smoke, bear in mind that most (all?) battlefield lasers are IR bandwidth, and I'd say most modern LRFs (used jointly with TI sights) use the same bandwidth as thermal imagers, so if thermals see through smoke, the laser penetrates smoke as well. So to simplify, the laser rangefinding ability gets the same limit as the vision.
QED or nearly so