As said earlier i would probably go with having interstellar drive requiring either canceling masses or trojan points idea.. Which translate to different lagrangian points (namely 1 or 4 & 5) and certain recharge time (perhaps even a day or so) and/or other limitations like requiring fueling... And then adding fluff for additional interplanetary - ie. much more efficient and capable of operating in gravity well but a lot slower - FTL drive, like something capable of just single AU or so skips with sizeable recharge times (like 30 minutes) with each skip.
Such fluff could explain the existence of convoys which are sorta odd in FS universe as well give some grounds for further fluff involving MAC type ships.