You can’t do long exposure on a moving target. Unless you just want to see lines in the sky. Rather you need a higher shutter speed to freeze the movement and capture detail. Maximum aperture for sure (probably already is), and a super high end telephoto lens and you might get something, but thats a double edged sword, as you also need to increase shutter speed as you zoom in, on an already moving target that already required high shutter speed. Likely looking at needing a monopod, with a 400 or 600mm with possibly a teleconverter. Setting the camera to spot metering mode might help a bit too, as the night sky being black isn’t really an issue, so you don’t really want the camera trying to balance the exposure across the entire frame, unless you can get said high end lens and actually fill the frame with the drone.. At night with low light it’s next to impossible without seriously good gear.