I'm planning to release a mod with on_chunk_generated event handle and i found what sometimes RSO generate resources over entities already placed by my mod.
I have my own check to existing resources before placement, but it works only if game generate resources by itself. Otherwise, seems my mod work faster than yours.

Something like as adding surface.count_entities_filtered check somewhere in roll_chunk function @1426 with custom type and ghost_type tables, also with invert option, which i can modify on final-fixes stage. Couse there is no collision mask for buildings as i know.