Sorry if this is a noob question, but I found it difficult to test in game. Does it spread purely X tiles from the generator? Or does it add it's influence growth somehow to your total border regardless?
In other words, if I have strong influence generators on my empire's borders, does it help my influence at all to "backfill" with cultural starbases in the inner regions of my empire?
Does it help at all to, say, build a couple of influence buildings on random inner planets, or am I better off making one "pure" influence planet and focusing only on making influence on border worlds?