With 5 LY hexes, that's a lot rarer than you'd think. The Pelaides Cluster and the Hyades Cluster come to mine as the only two actually
I counted well over 100 systems within 5 LY of each other, though wriggling the hexagon a bit would reduce that. How do you plan on dealing with those situations when they do come up?
And what happens when, since hex jumps and systems are so precise, when 2 systems six 5 LY hexes apart are actually 35 LY, or there is some wacky shortcut that allows you to get to a planet 100 LY away with just 3 jumps?
Heck, even if those are persistent issues what you are doing looks great, and I can't wait to see the whole inner sphere!