Based on recommendations, I bought the no-excuses overhead bag to add some out-of-the-way storage to the Z.
I had to remove the roof to make installation easier. I thought at first the bag was too small and the velcro strips were too short, but after putting it out in the sun after the initial install, it stretched out enough to get all the velcro tight and secure.
I put the rain gear and a few odds an ends in it to free up space in the rear storage box.
Went for a short ride and you don't even notice that it is there :-)
I'll put the little bluetooth speaker in the mesh pocket for the next ride.
Also replaced the twin-air with a new Uni-filter. The Uni is definitely more dense than the twin.
I think the twin-air with the extra cover is probably ok, so I'm considering swapping back and forth between the two, keeping a clean one at the ready and allowing me to clean and prep the dirty one at my leisure.