The same SET USER 640184.571119 command works on my 2012 Brother MFC-9460CDN.
It also works on my Brother HL-L3280CDW
No issues getting it to work on my MFC-L3720CDW
This is awesome
It also works on my Brother HL-L3280CDW
No issues getting it to work on my MFC-L3720CDW
This is awesome