If you're using 3rd party toner, yeah, you gotta swap the little chip, but you can run the toner well past when the printer thinks it's empty by following the reset process: https://www.tonerparts.com/blogs/brother-1/how-to-reset-the-toner-cartridge-for-your-brother-mfc-l3710-3730-3750-and-3770 . It is very fiddly getting to that menu the first few times, but once you've got the hang of it it's pretty straight forward and lets you just keep rerunning the same toner (or 'toner' if you're swapping the chip) indefinitely. For what it's worth, given the longevity of the drums, I've found it easiest to just buy the Brother toner (it's only like 2-3 dollars more expensive than the 3rd party where I am, and is available in stores locally vs having to order from Amazon) and just run them until they're dry by resetting them 2-3 times before replacement.
Edit: Oh, I forgot to mention: print quality does start to degrade significantly after the reset about 1/3rd through the second 'tank' each drum provides. We use the printer primarily to print off sewing patterns, so this doesn't matter until it's illegible for us, but depending on what you're using it for that may be worth keeping in mind when you're resetting them instead of getting new ones.