Quiet generators are almost like unicorn sh*t....
Mythical... Yes if you spend top dollar on a Honda I series.. It'll be a mildly irritating drone rather than rattling your teeth out loud.
I went solar/VSR and decent battery bank for silent power and eberspacher for heating...
Eberspacher wasn't cheapest BUT as we use the van all year round I wanted reliability AND safety rather than cheap and Chearful till it packs up...
Let alone someone not bothering with fitting a reliable overheat cut out.
The only true silent generator is, one with a bag of sugar in the tank