A company named Wacko products makes an "RV Silencer" kit. Maybe someone can post on there experience. On the website they claim a large reduction and some online reviews say they do. But those who use it might help better.
You may want to repost as How good is RV Silencer kit from Wacko? to get better answers on that possible solution.
On mini-splits, I looked at one for my permanent mobile home and it wold come to several thousand installed. But --Oh are they quiet and efficient.
2017 SLX 195RB
2021 Jeep Grand Cherokee Summit L 5.7L V8
Andersen WDH hitch, Renogy 100 AH Lithium &
200 Watts solar panels from Renogy
Prev. '14 Jeep Grand Cherokee Overland, gas 3.6 V6