It would be interesting to test this formula. Substitutions of Phenidones in place of Metol are viable when the developer contains a secondary superadditive agent, but I would not expect using Phenidone only in place of Metol in a Metol-only developer would work very well, if at all. For example, you cannot make a Phenidone-only version of D-23.
Perhaps the relatively high pH of this formula helps, but I'd still expect either very low contrast or high fog. An interesting formula.
I'll post a few other interesting Axford/Kendall things from Haist in separate articles.