Ford builds the F53 chassis with absolutely no idea what it will end up being built into. It could be a bus, wrecker, hay hauler machine or even an RV. Based on that , they design a simple generic transmission program that works but is not suited for the purpose we want.
If you read your owner's manual you will see that Ford does not want any mods made to the vehicle or warranty work could be denied. Even mods that actually help and are needed.
Running the 5 Star tune is similar to upgradeing Windows 8.1 to Windows 10. Same computer and hardware but different operating system. You don't like Windows 10, you can change back to Windows 8.1 with a few mouse clicks - right?
With 5 Star tune you improve the operation of the RV in a positive way but still remain able to return it to stock. However, a slick tech could find you have done this and could - I repeat, could deny warranty coverage to a problem he can say was caused by the tune. Since the engine software is not effected much, chances are you will never have an issue.
I am not sure when they started, but I do know 5 Star has been offering their product for the Ford F53 several years and I could not find one single complaint when I researched buying mine. There is plenty of info out there if you look. I do know those who have tried it, love it!
2015 Jayco Precept 35UN
Towing JEEP TJ with Roadmaster plates and bar w/Blue Ox Patriot brake
an Aluma low bed trailer with HD Road King and/or Polaris RZR onboard