Agree. Most rooftop units designed for RB use don't even have charging ports; they aren't designed to be recharged. This means the tech has to cut the refrigerant lines and solder in both low pressure and high pressure ports, creating additional potential leak points. Then find the original leaks and fix them, vacuum the lines, replace the filter drier, and add a new measured refrigerant charge. IF you removed the unit from the RV and this work was done in a shop, it might be done well. Then you still have an old unit.
In my opinion, better you spend the money to replace it with a newer, more efficient, quieter unit.
...or wait until @Hotrod and I finish designing our variable speed compressor RV heat pump and get it in production. (🤣 You might not want to wait that long!)