I have a Givi AF-330 on a GSA.
It does not use the extra support U tube and the adjustable mount bushes may need the three tags cutting short. TBH they are no loss so don't worry about that. You can fit your own cross tube (e.g. to carry a Sat Nav) with P clips to the screen top mounts.
I also have a support bracket on top of the instruments frame. It stops the screen vibrating. Lateral wobble/vibration isn't bad but the bracket stops it completely.