I've fitted a US20 to the rear, it's a bit fiddly but can be done. I'm fairly happy with the result, IMO it's more secure than the 1199. Away at the moment so from memory...
Use the straps/loops that come with the Kreiga kit, cut them down to
Front 11.5cm
Rear 14.5cm
Use a flame to sear the ends and stop them fraying.
The front ones I fit using the grab handle bolts. I punched a hole in the strap for the bolt to go through & used the metal handle mounts to clamp it in place (I cut the grab handle off, pointless anyway IMO).
The rear ones are the trickier, you'll need to take the tail apart. There are 3 main bolts that hold the tail in place, it's the aft one that I used for both the rear straps. Again punch a hole in the strap near the end of it. The bolt should go through the seat section, through both the straps and then into the thread. That's the awkward bit, getting it all lined up. Once the bolt is tightened they should be clamped firmly in place. The routing of the strap up should be fairly obvious to each side, I think I just ran them outside of the black plastic cover.
As they were a PITA to fit I leave the rear ones in place, they're hidden anyway by the extra fairing pieces, the front ones I just fit as needed. Just double check the length of the straps before you cut them, it was almost a year ago I fitted them.