I have Zega Pannier, had then for years, which I re-drilled and mount to SW-MOTECH pannier rails. These rails are easily removed when not in use plus I have a set of rails for my Tiger 800 and had a set on my KTM 1190 Adventure. I just swap the boxes from bike to bike.
The SW-MOTECH rails are a different shape and thinner than the TT rails so I removed a few mm from the backs of the mounts in a lathe.