I've tried to add the support of Fenix 5X to the JNX Patcher, and the patch itself seem to be working fine.
Unfortunately Fenix 5X devices have some kind of firmware checksum validation, and I could not find out how exactly it works. The testing with remote testers couldn't help either.
I hope if I can get my own Fenix 5X, I'll be able to figure out the validation logic, and make the necessary changes to the patcher.
I cannot afford all the money necessary to buy the device, so I'm asking the interested persons to help me fund the purchase.
Thanks in advance everyone!
I alredy have: 147 Euro
Necessary amount: 600 Euro