Is it possible to connect a blueprint with another? For example I would like to have blueprint A (base) and stick a tower to it (blueprint B)
Spanj did a video of this a couple of years ago. I'm not sure if it still works, but you could give it a try and let us know.
Much easier to just copy and paste the relevant bits of base and manually get rid of the residual illegal blocks (core etc).
I did it ages ago in this video as well, this still works, you just have to remove the core from each part.