Fortunately for the perverts that actually
want to see smoke coming from their tires, Scawen has already mentioned improving the smoke.
I imagine that the next patch will have smoke coming from every burning hot section of tire, whether or not that section is touching the ground.
I don't think that the computing power required to handle smoke collisions is ubiquitous among the LFS userbase.

Once we have smoke collisions, we'll naturally want sophisticated fluid dynamics
If collisions were to get attention, I imagine most LFS users would prefer that car-launcher-barriers were fixed.
As someone that spends most of their time in LFS drifting, I can certainly relate to people that want the smoke improved, but there are a lot of other things that I would like to see first.