DC compressor refrigerator
Gordy, we've had experience with several 12V refrigeration systems in past "RV's" (sailboats which we lived on for years at a time), including a component system made by NovaKool. Offering summary comments about the practicality of 12V refrigeration for an RV is difficult as a unit's performance is dependent on many variables including box size, whether you're trying to include a freezer section (which usually requires a holding plate), amount of insulation, ventilation of the compressor unit and, not the least important factor, whether the unit offers a water cooling option using a loop to/from the water tank. I can assure you the more battery charging sources you have, the better. A careful energy management study, with multiple 'what ifs' considered, would I think be essential. Personally, I think having the absorption refrigeration option is liberating in that it makes refrigeration available with a lesser penalty of 12V energy management and avoids the weight & expense of the additional electrical support a 12V system requires. But there are advantages with a 12V system, as well. It should be less trouble prone mechanically, and it doesn't care how level your RV is. Another advantage is that small, well engineered 12V units are available off the shelf with a well balanced blend of box size, cooling capacity and insulation. But we're talking shoe box refrigeration choices when compared to the typical RV refrigerator in most travel trailers and campers. As for the 'dorm refrigerator' products (like one shown in the NK webpage you linked), they will be energy hogs and ill-suited for an RV unless it is permanently connected to 120V AC.
So if your refrigeration needs are modest (and exclude a freezer section), you are adept at designing and building up ayour own top-loading box (which I had success with after some research) that fits the space your RV has to offer, and your RV has more than the typical 2 x 12V 100AH batteries plus multiple charging methods, then it could be a viable (if somewhat expensive) option. OTOH I don't think the effort and expense is remotely warranted if you're just trying to avoid turning the LPG on & off when driving.
Hope that's of some help. Good luck with the research and best wishes,