[Relayer]

Alan, thanks.
just make some experiment - mix next solution like to Mark formula
Water 1l
Sodium sulfite 90g
Phenidone 0.1g
Ascorbic acid 8.5g

because I haven't metaborate, I replace it with borax+sodium carbonate. 6.7g of Sodium metaborate 4 mol = 6.7/101.83 = 0.066mol. because 1 mol of borax have B₄ (metaborate have B₁) I take 0.066*381.37/4 = 6.3g of borax Na₂B₄O₇·10H₂O. mix and check pH=7.8
after this I add 10% solution of sodium carbonate slowly and check pH. at pH=8.3 I'm stoping and calculate amount of Na2CO3 - its 2.33g/l. so result formula is:

Sodium sulfite 90g
Phenidone 0.1g
Ascorbic acid 8.5g
Borax 6.3g
Sodium carbonate 2.3g
Water 1l
pH=8.3

LegacyPro (Neopan) 400 @400 8min 21C (time from digitaltruth for XTOL stock) - negatives slightly dense than I expected. can't make comparison with XTOL because haven't it. Mark, maybe you can make this formula and test it.