So can a VTOL using a VTOL mast to peek above LOS blocking smoke fire a direct fire weapon through smoke that blocks LOS to the VTOL body? Obviously it would be taking the +2 penalty for firing through smoke that doesn't block LOS, since the mast would have to be drawing LOS from a hex where the LOS passes through either 1 hex of heavy smoke or 2 hexes of light smoke for the VTOL to be in a hex that is LOS blocked by the smoke.
Lets paint a picture.
The VTOL is hiding behind a hex of heavy smoke, with a target 6 hexes away. The target is hiding behind a hex of light smoke.
If the VTOL uses a mast to peak above the heavy smoke and takes a shot with a large laser. That shot only has a +1 TH for the light smoke adjacent to the target.
It seems reasonable to me.
There might be an argument for a 1 point TH penalty, simply because your point of view is 3 meters higher than normal.
I don't think a hull mounted TAG could work in this case though, because TAG is a low powered spotting laser, and may not be able to cut through the smoke, like the above mentioned large laser. Although if you have a
mast and TAG, why would you put it anywhere but the mast?