Gerald, it would appear that this developer goes back to at least the early 1990's when Kodak published a document on Environmental process development, they din't name it as D96a rather just as an Ascorbic acid version of D96, this is the same in the MSDS sheets and hazard labelling which call it D96 Ascorbic acid. The formula is identical (both using Potassium Bromide) except for the substitution of 2 g L-ascorbic acid for the 1.5g of Hydroquinone.
Tests of the two versions showed that the graininess was identical, the ascorbic acid version gave a slightly lower D-max and that increasing the Ascobic acid level did not have the expected results (of increased activity). In addition the acsorbic version oxidised faster so didn't keep as well.
Kodak did publish some cine film developers with the option to use Potassium or Sodium Bromide giving the alternative weights needed.
Ian