We run third-party toner in all of them, and they'll keep printing until the print quality fades.
I personally haven't tried refilling toner cartridges in a long time, it's not worth it when third-party toner cartridges are as cheap as they are and the Comprenew up the road takes the empty ones back for recycling.
At work, we have an MFC-8950DW laser printer and it's not very good. It leaves streaks on the paper and the toner doesn't seem to fix properly all the time. I end up with printed pages that smear or the type rubs off. That printer replaced a much older Brother laser and it was better. We "upgraded" simply because drivers were not available for 64-bit Windows.
Brother HL-L8260CDW
https://www.amazon.com/gp/aw/review/B06XDS1XW7/R2MQHUVV9JX7N...
There's also a fill port right on this printer's starter cartridges. Brother even provided a removable and reusable fill plug.