So, first good news, it works. I made a quick test, developing a fully exposed snippet of Tmax 400 at roomlight. 3 minutes part A and 3 minutes part B, fixed as usual. The snippet is all black with a good density. So we can be confident that it will also work with real pictures. So here's the recipe:
Part A
vitamin-C 15 g/l
washing soda waterfree 7,5 g/l
sodium sulfite 35 g/l
potassium metabisulfite 6 g/l
phenidon 0.3 g/l
pH: 6.8 (bingo!)
Part B
washing soda waterfree 20 g/l
sodium sulfite 65 g/l
pH: about 11 (another bingo)
I diluted in the given order. Phenidon may take some more time to dilute 100%? So we will see how it works with real images, if we get even development, base fog, film speed, grain, sharpness etc. ?
Best - Reinhold