I run a multifunction colour Brother as well. I’ve used it with Brother and various other brands of toner without issues. It will keep printing even if a cartridge is empty. Finding consumables is easy. It runs great from Linux (duplex scans and prints), Windows and mobiles through the LAN. It’s a great machine. You can even override the “low toner” alarm and basically double the life of your cartridges (maybe shake them a bit beforehand). You just swap them out when the quality visibly degrades. I think I bought it for about 400€, it was well worth it.