@slyctopus,
with some inginuity there is for sure a way to install kind of rack. Even from some other brand or model. But would use your rear shocks upper points and then overload and extend your rear. How about thinking to use a fuel tank bag? In a combined strap/magnetic version maybe. Had a Yamaha XT 500 long time ago and added a carrier there behind, was not happy with street cohasion afterwards and went to mentioned tank bag, which made a calmer ride. At least for me, l'm short and had a windshield mounted for longer rides.