Floor lamps can be placed atop other floor lamps. I'm guessing that floor lamps have no collision with buildings so that you can place them under other buildings, but it leads to strange behavior where they can be placed beneath other floor lamps infinitely. It also makes it so that you can't place a blueprint of a new floor lamp over an old one to copy behavior, as it just creates a second lamp with the new settings.

Is it not possible to limit them to colliding with only themselves, or create a whitelist of stuff that they are allowed to collide with? (Honestly it seems strange to have them not collide in the first place, but that's neither here nor there.)