Yes, it was a surprise, but I did try it on a totally different model phone, and as I mentioned above the modded file was located in a different place to the stock G4 one.It shouldn't have caused so much trouble. It worked successfully on each of my friends Moto G4 Plus running stock ROM.
No real harm done, I could restore my device and get it back to normal again. But I did think it worth mentioning in case other non G4 users tried it like I did.