The hike in pH seems to be mainly so Agfa could get more activity out of less developing agent cutting the cost of manufacture. This was what Edward Zimmermann and other photographers mainly German where complaining about in the past and why some prefer Calbe R09.
In Europe, (less so in the UK) Rodinal has always been main stream developer, it was one of Agfa's main film developers, I've no idea how it sold in proportion to others.
Are you saying that Ascorbic at pH 11 is the cause of the fogging ? Or is this not due to the fact that a high sulphite level's required as an anti-oxidant ?