We just found the modified time is part of the integrity check in Firefox sign.
Changing the modified time will break the Firefox sign.
Is there any approach that modified time could be skipped in Firefox sign checking?
I dont think so, because the whole point of signing something is to sign off on that specific state. When the last modified changes its no longer at that state.
Yeah, changing any file in your install directory or package is not allowed. If you need to save something, you should do that in a separate location in the profile directory.
The recommended location to save stuff I think would be the same way simple-storage module works.
https://discourse.mozilla-community.org/t/alternative-to-application-storage/3198/4?u=noitidart
Be sure to delete it on uninstall of your addon 