The cassette style is pretty new, and bidets are pretty rare here. There was a thread a few days ago...but I'm not sure how it compares between models. Here is a search for all mentions of the word "bidet" here in Forum land; https://tab-rv.vanillacommunity.com/search?Search=bidet
Agree with Dale, in a 320 with a cassette, I’d be concerned about both fresh water use and especially waste water use. I doubt a seat-type bidet could be easily fitted to a cassette toilet. A few people have installed the hose type inline on both the 400 and older 320 showers, so you could look closer at those installs and…