The OTU SDB's are frequently moved using "jump pods" (a jumpdrive and fuel tankage hulled vessel) that locks onto the stern, and moves them from System to system. Or even to outer edge in micro jumps...
For TNE era stuff, I utilized these in my campaign, as well as old X-boat Tenders to ferry up to 3x 200dtnlighters around in a pocket empire along a J-1 main.