I still remember we once discussed this and the idea was, that you may call a planer (just like a scout).
There ware some problems with that way idea:
- The flag spot needs to check weather the underlying BQ is at least medium
- Neighbour building spots need to be blocked while a planer is on it's way
- The flag spot needs to check weather finished buildings are blocking
- It's not transparent for players why one may not call a planer
So another idea was adding an additional building - which will be destroyed after planing.
I'm still curious why we do not have anything about that on github, pretty sure we discussed this already somewhere, somewhen :D