Yeah I had that same issue. I asked about that earlier and there is no way to make splines visual only.
So I had to fix it by placing all the walls as objects and make it visual (quite a pain in the ass)
As opposed to the oorah and a molotov against an MG. Come on, there are problems with the soviet faction but these complaints are getting more and more ludicrous by the day.
In a 1 con vs 1 mg you can suppress the con before he throws a molotv and then back up your mg42 a bit. A maxim will always eat a rifle nade which deals significantly more damage than a molotov.