I would love to see reusable drones and have several ideas for how they could be implemented if you're interested:
1) New variant of the mod
2) Researchable upgrade to hubs allowing them to catch drones
3) VTOL upgrade, could also make delivering faster
4) Most radical and somewhat redundant: Current hub used for mid range quadcopter drones (think Amazon delivery drone attempts) with runways for current long range plane-style drone
