Is it possible to use existing mesh or Spline in the scene to assign or limit area of foliage generated?

Hello guys. Although procedural foliage blocking volume can limit area that foliage grows, I still have following doubts:
Comparing with using foliage blocking volume, would it be faster and easier if I delete plants by Paint under Foliage mode?
In my projects, usually there are a lot of buildings in surrounding area. Therefore I need a lot of foliage blocking volume. That is great workload. Why not to use Paint in Foliage to directly generate plants?
In my view, if procedural foliage spawner can not use existing actors or splines in level to assign or limit area that plants generate, then, if I use big size Paint in Foliage mode, it would be almost same effect with spawner, in which case advantage of spawner does not shown.
So I would like to know whether my wish towards this issue would come true?