You can't build the factory on ores, you are need to remove it before. Compatible with all mods, works in multiplayer and costs no extra UPS. (added 'resource-layer' collision mask to some buildings).
It would be nice if you could add "Landfill"tiles as allowed (not forbidden) places to build anything.
You are right, I don't know why the Landfill has collision mask to 'resource-layer'. I will add it as an option because of other mod compatibility.
It has no collision in vanilla:
data.raw.tile.landfill.type = "tile" data.raw.tile.landfill.name = "landfill" data.raw.tile.landfill.order = "a-d-a" data.raw.tile.landfill.collision_mask = {"ground-tile"} data.raw.tile.landfill.layer = 57
