On the subject of buffering with borax or borax+boric acid, this thread may be of interest. There is also a post there by Ian Grant where he provides the formula for the Wellington Borax MQ developer which is actually an older formula than D-76. As Kodalk, wasn`t around back then, think of the formula as being D-50, the forerunner to DK-50.
Ian has worked as a chemical analyst
and has an excellent source of photo-formulae..
Borax Project.