it would not change much of the existing gameplay bar from one or two things.

a new option in the planets tab called "search star system", it has an increased chance of scanning for new worlds but the system would only have a limited number of worlds, for this to be fair it would require 10 or 15 energy per world in that same system rather than 5, with ajoining worlds under the same players control it could provide a small bonus to each world involved as there is fast trading between worlds (passive description, will not affect game)