@steve3b3 & @catcher can chime in with opinions too as they both have the 2018+ models and way more miles on them than my almost 500km.
I'm happy with the stock windscreen.
I bought a Mustang seat, and find it very comfortable. I'm 5'10", and can flat-foot at a stop. I lean a bit forward while riding, and don't touch the back rest unless at a stop. I do have a bit of sholder ache after an hour or so.
I lost the heat, though, when I was troubleshooting my problem connecting to my helmet. During that, I disconnected the battery, to reset the ECU and Audio Module. When I reconnected it, I apparently burnt out the temperature sensor thermistors in the seat. Since I was out of warranty, and the cost to replace them approached that of a new seat, I passed. They did send me a bunch of Mustang swag, and a module to make the bike think all was fine, vs the constant blinking seat light. They also offered to sell me a seat and passenger armrest combo, which apparently had some different thermistors. Brenda didn't like the larger armrests, because they'd make it harder to get on and off the bike, so I passed.
I like them as a company, and they're down the street. I'd find out if this is just my problem, or generic, and did they solve it.
Or try another vendor.
I used the OEM seat as a comparison to what the Mustang resistance reading were.
I've been thinking that a PTC in line with the thermistor would have prevented this. If they're sensing, they're probably not passing a lot of current, normally, but I guess there was a spike, somewhere.
I added Goldstrike footrests and only use them on longer trips.
I also added a Goldstrike cup holder, after stopping at a McD's drive through during COVID, got my meal and coffee, and found myself with nowhere to put it all...
Honda trunk shelf.
Honda Aux lights.
and...
I don't use Sport mode that much, actually.
If I'm stuck behind slower traffic, I'll put it into Sport mode, for a brisk pass in our short passing zones.