IIUC, OFA upgraded your 6131, adding a eeprom and maybe adding some setup codes.

Either they didn't add the right setup codes, or they didn't communicate to you which setup codes they added, so it still didn't work.

So you found and added the right upgrade by JP1.

Probably by now they know what the right setup code is, so the next person sending in a remote for upgrade (or using the phone for a phone upgradeable model) will get the right one.

Using a JP1 cable can certainly get you better results than merely getting the right upgrade from OFA. But for those who don't want to use JP1, your experience shouldn't convince them that OFA can't do this upgrade correctly.

An OFA upgraded remote should cost a lot less than the $50 quoted above.

BTW, before loading the right upgrade, did you download and save the eeprom contents as upgraded by OFA to see what they really gave you?