Winnebago has had them as an optional upgrade on their Views/Navions for a couple of years. Standard batteries are AGMs, or upgrade to lithium, for a few dollars more (~ $5000?). It became an option when the new flat top cab over was added. Same year.
Winnebago used the Zamp Solar Charge Controllers ZS-30A in my 2018 Navion. It came with a pair of cheap FLA batteries, but the solar CC has an LiFePO4 charging algorithm, which is almost the same as the AGM charging algorithm. I use it now, after swapping in a couple of Relion 100Ah RB100-LT lithium batteries back in 2019. Works just fine. I also have a Progressive Dynamics PD9245 converter/charger, to which I added a Charge Wizard remote control pendant. With it, I can manually boost the charging current to the lithiums when I'm plugged in, if they need it.
Mike. Comments are anecdotal or personal opinions, and worth what you paid for them.
2018 (2017 Sprinter Cab Chassis) Navion24V + 2016 Wrangler JKU (sold @ ????)
2016 Sunstar 26HE, V10, 3V, 6 Speed (sold @ 4600 miles)
2002 Roadtrek C190P (sold @ 315,000kms)