ErnyTech [1] filed an orphan request for brscan3 [2]:
This package has not been updated since 2016 and the maintainer does
not seem contactable.
Currently this package is not fully functional mainly because the udev
rules (50-brscan3.rules) are missing for some models of
scanners/multifunction printers.
I would like to take the package to (try) improve support in all
printers that use brscan version 3.
[1] https://aur.archlinux.org/account/ErnyTech/
[2] https://aur.archlinux.org/pkgbase/brscan3/