One thing I have been trying to get my head around is a sensible distance limit to FTL travel; something that can be vaguely justified in the same way as the FTL rules around flat space and potential energy can be.
One thing I will try is not limiting the distance, buy limiting the precision. In other words, a rule something like: "You can jump to any star you want provided that there is no star closer to your start point and within 20 degrees of arc of your destination as seen from your start" Angle would go up or down with risk, technology, prep quality, etc.. Once I have the database ready (getting close) I will see what this means for communications maps.
I have also been thinking of having the actual jump take zero time. I want to have as few rules as possible for "jump space" and not spending any time there makes that simpler. One of the implications is that one could have FTL ships (or drones) jumping back and forth between stars transmitting and receiving message traffic at both ends; a process that could make communications time to a distant colony as little as 24 hours assuming FTL transit points are 2-3 light-hours apart.
I'm not sure I see this as a problem. It would not be cheap, it would be easy to cut off, and it does provide some justification for a "strategic player" getting some information from the frontier in a timely manner.