Hold on while I put on my Flack Jacket
I bought my first absorption refrigerator in 1994. I ran it while traveling full time in my bus for five years. Then one morning I woke up gagging on ammonia fumes. Eyes burning & watering so bad I had a time finding the front door.
My experience in those five years that the "must be perfectly level" is WAY overstated. Let's call it 1800 days parking in all sorts of places. Some far enough from level that I had trouble sleeping. The fridge didn't care. I found that outside temperature did have a significant effect on performance. Keeping ice-cream could be challenging in hot weather.
I also found that they are energy pigs.
Ventilation is also critical.
So, I have owned three rigs with absorption refrigerators. I wound up replacing all three with conventional refrigerators. In my current bus I am starting out with a conventional refrigerator.
In my current travel trailer i replaced the 6.8 cu.ft. absorption refrigerator with a 10.8cu.ft. conventional refrigerator and it fit nicely with only a minor cabinet modification. There was a storage compartment under the fridge that was pretty useless. I took the door off, removed the shelf and cut the rail. 30 minutes and we were ready to go. The extra space compared to the old one is fantastic. We spent a month in Mexico and grocery shopping could be a challenge in some places so the extra space made the trip so much easier. Oh... And it keeps my ice cream solid when it is in the high 90's outside.
I speak only from my own experience with RVing over the last 25+ years. Around 8-9 years of that was full time. I am calling "full time" any time we were in the RV for three months or more. 44 US states, 3 Mexican states and 4 Canadian provinces.
I am not making this s#!t up