Land is no longer free. No more reckless sprawl...
Building in unclaimed territory is forbidden. Claim chunks with points earned by researching new technologies.
Choose your chunks wisely!
Well, I didn't install this mod to try it yet and this idea is solely based on the little info available about the mod we have.
This is a interesting mechanic and would be great as a planet specific characteristic... so, my suggestion is like the tittle, add a option to choose a single planet to apply this feature.
If a planet dev approaches me asking for this feature, I'd be happy to oblige, but I think for simplicity I'll leave it as its own challenge mod for now.
