I've just had a pair of sliding screened windows installed in the side doors of my 2017 LWB TC cargo van:
They are model WD07, available here:
http://teardroptrailerparts.com/Windows___Doors.html
Not the highest quality, but the price was right, and they work just fine to give me a view of the passenger-side blind spot, provide cross-ventilation, and keep the insects out. They were the largest of the mass-produced windows that would fit into the limited space of the TC Generation 2 sliding side doors that I was able to find.
I can provide full details of the installation process if anyone is interested.