Hi Tilly
I did years ago on a 2008 12GS, was fine size wise, just a bit more of a faff filling up than a tanklock givi for example. I don't have any pics but as long as you don't want quick access to stuff then its a good alternative.
I think I have a Kriega tank bra in my garage. Away until tomorrow night, but can take a look and you are welcome to it, if it is still there. I used it on my 2016 GS with the US10, and it worked fine. Never tried it on my current GSA.
I still have it, it just needs a wash. I'm not a subscriber, so can't message you through the site. So if you message me through Facebook, I will send you some pics https://www.facebook.com/mark.crumb.52
I’ve used one on a 1200GS many times. Fits and works fine. TBH it’s a bit of a faff as a tank bag because of the roll-top opening/closing but if you’re ok with that the US5 and tank adaptor together are very good kit.