Once iOS 8.1 stops being signed then its a risk getting into files like that. And carriers continually change and update tower and carrier settings for certain devices and firmware versions. Don't think it's something manual users should be altering on their own. You could see improvement now but if the carrier decides to change things on their end you could be stuck with many issues.
No pun towards the OP. He's just trying to help others.
I'm just letting ya know about past experiences and possible implications.
these hacked carrier packages usually have a "newer" version, so your phone doesn't detect the official carrier packages and update to that. for example, let's say the official carrier package is version 16.0, this carrier package version might be 16.5 or something
Is everything completely reversible with this commcenter hack?
Cause when AT&T releases voice over LTE officially those with altered carrier settings would be stuck needing a restore.
i do believe it is completely reversible. my iphone 5 on 7.1.2 is still doing fine after reverting it back to the official carrier package. when i tried out a hacked carrier package a few month ago, there was the official carrier .ipcc file to download as well, which I used with itunes to bring it back to normal
i've never actually dealt with upgrading/downgrading the carrier packages from the device, always with iTunes so not sure if that's a factor