An update:
Trond has tested his new ascorbate two-bath developer for two months, and posted results to the ascorbate-developers blog at this link: http://ascorbate-developers.blogspot.com/2012/02/lomad-diafine-clone.html
He includes some high-contrast scenes which this developer tamed well.
He named it LOMAD -- Lazy Old Man's Ascorbic Developer -- so it should appeal to most of us.
I made some test 16x20s from some 6x7 TMAX400 that had been processed in Diafine. Up close, you can just barely to see the grain, but it is nearly invisible. I'm really considering returning to Diafine for all my work.
It seems to be the accepted wisdom that in part full bottles hydroquinone based developer (Diafine) will oxidize more slowly than ascorbate (-C version).
in solution with Na2SO3 hydroquinone oxidize to hydroquinone monosulfonate:
C6H6O2 + Na2SO3 + O --> C6H5NaO5S + NaOH
as result we have extra NaOH and increased pH