I skipped a lot of comments. I also use Brother-MFC like your, but different module.
Honestly, I don’t use scanner driver in Linux, because the printer has its own driver for scanning images.
I love using scanner via FTP or SFTP by pressing the button in the printer that sends the better quality image to my Linux home directory ~/Downloads.
Then I put paper in the printer then scan it immediately, that is faster than I go to my PC and click scan.