do you know if there's a mac OS version of that flasher by any chance? I want to test my progger with that at some point, but I don't have any windows machines

yes it does have a mac OS version. You can check it at https://github.com/melka/gbcartflasher . I do use mac but I am just too lazy to try to install that on my mac, so I just used my old Windows laptop for that job.

cool, thanks :) I consider getting an old windows box myself. My cart flasher should be really fast, but I never got it working quite right. I ended up putting a rom into the flash of the arduino (based on a bigger avr with a lot of storage), burn the avr that then burns my cartridge... so I crippled my in theory faster chip to a small cartridge size.