Yes, we did order the Super Solar Flex package, but ETA is likely November. So, can't report yet, but will definitely do so later in the year.
As to Montana and solar, there are 3 options (and I believe this includes the HC models as well, but my research was for Montana only...)
1. all models come with "Solar Prep". What that means for 2020 and 2021 models is that there is a connector on the roof, then 10 ga wires run into the basement behind the rear panel of the main storage bay on the curb side. Also, there are 5 outlets pre-wired (this is a huge timesaver!). They include the TV cabinet, recliners, kitchen popup, bedroom outlet by the dresser and... sorry forget the last one
2. Montana Solar Flex package. This package includes a single panel (now 300 watts) along with a Jaboni 30a MPPT solar controller and a 2000 watt inverter. The inverter powers the above outlets.
3. Montana Super Solar Flex package. 1200 watts solar, dual MPPT controllers, 3000 watt inverter, 510ah lithium batteries and all the techno goodies for power management. Wired to run the whole coach including all outlets, both ACs, etc.
So, no matter what you are ready to have solar installed. The decision can range from installing a single panel and controller to charge your single 12v lead battery, all the way up to the Super Solar Flex package. A lot of options.
What do you intend to do with your solar install? If you'd like to share more, I can direct you to the research I found.