So Just to clarify my idea a little further after reading through the comments. I picture it more as a guide, so if you try to place something outside the blueprint or as a different material it would still let you, no restrictions. This wouldn't be as strict as the radar towers.

I love the idea of voting to use it. I picture this working most efficiently with a set party of friends, but voting would allow this work while playing with randoms or more than one constructor.

When it comes to the terrain and floating atlases etc, again I see it as a guideline. So if a piece is on uneven terrain, it could just be red rather blue showing that piece wouldn't work there and you'd have to adjust accordingly. Also, you should be able to just toggle it on and off as you please so you can use the pieces of the guide that will work, and turn it off to freestyle the rest to make adjustments. I can see it being toggled by clicking in both thumbsticks simultaneously (pc some button).

This would be mainly effective for the core design around the objective itself, not necessarily the whole base and all its traps. So the sandwich method or the pyramid mainly showing what your idea is, then traps and outer walls can be freestyled.