Hey that’s really helpful, thanks for sharing! Brother toner is about 3x more expensive for me.
I have HL- version of same model. Doesn’t have exactly the same toner options as in the link, but I’ve spotted a ‘Reset’ button hidden up the ‘Toner->Calibrate’ menu. Strongly suspect that’ll do the job!
The chip transfer thing has caused me issues in the past though, with the printer refusing to accept the toner even after switching them.
I had this setup but during a reinstall/update Windows still destroyed Grub. You have been warned!