Something I've not seen before

I agree. That has GOT affect the handling.
I did an experiment once where I mounted a 3 foot length of aluminum tubing to the handlebars of my Honda Trail 90, sticking straight forward. Then I mounted my tiny video camera on the end of the pole looking back at me. The camera only weighs less than half a pound. Wow! That stupid arrangement made the bike handle VERY badly. Something about the inertia of a half pound of weight swinging back and forth at the end of that three foot pole made it very difficult to keep the bike in a straight line.
I can only imagine how much those saddlebags affected that bike that you saw.

Yeah still considering removal of the front Pacifico faring off Winger hate the way he feels in the wind. You know it also seems to confuse birds, never have I hit so many birds.

I've seen leather bags made to hang off the highway guard right below the fairing, but never seen anything like that actually hung off the fairing itself.

I've seen someone hang a length of 100 mm/4" plastic pipe on each fork, capped top and bottom. Gave them a fair bit of storage and didn't affect the handling very much at all.