I also did that once by accident. Worked for a few months, then I had to replace the correct developer type, because the copy quality became bad.
I figured as much because of the toner. Ya gotta do what ya gotta do, so in goes the B121 dev. It will be corrected within a short period of time. I hate to be a hack, but if wasting a bag of developer temporarily keeps a good account up and running , I'll do it.(SC 500, main motor lock, dev unit locked up). Thanks guys for the input.