FriedChicken : I will compare all permissions, but before all, did you test the Brother packages? In my case, the original Brother packages does not modify anything in /usr/Brother/inf when changing parameters through cupsys, so we may lose time if we try to find a difference between the Brother packages and our packages if the bug also exist in the Brother packages.
/usr/./././Brother/ = /usr/Brother/, it's a trick to avoid /usr/local/Brother even in binaries, you can ignore this.
FriedChicken : I will compare all permissions, but before all, did you test the Brother packages? In my case, the original Brother packages does not modify anything in /usr/Brother/inf when changing parameters through cupsys, so we may lose time if we try to find a difference between the Brother packages and our packages if the bug also exist in the Brother packages.
/usr/./././Brother/ = /usr/Brother/, it's a trick to avoid /usr/local/Brother even in binaries, you can ignore this.