I shoot two formats mostly nowadays almost at the opposite end of the format spectrum - 16mm cine and 8x10 ...

I do reversal developing in the 16mm and Pt/Pd contact printing with the 8x10.

For both formats I use Kodak D19 - its great for the higher gamma needed for Pd prints and is listed as a good substitute for D94 in the 16mm world - However, as my supply is running low and I dont want to order from overseas any longer I want to mix my own with chems bought here - the mix is as follows:

Water at 50C (125F): 500 ml
Elon (Kodak's name for Metol): 2.0g
Sodium sulfite, anhydrous: 90.0g
Hydroquinone: 8.0g
Sodium carbonate, monohydrated: 52.5g
Potassium bromide, anhydrous: 5.0g
Add water to make 1L

Since I am investing some time into make this myself I thought it would be prudent to find out what each component of the mixture does and what the effects on film would be with addition of extra or less of these components... A sort of reverse engineer if you will

Any knowledge appreciated!

the reversal developing says I good putting in sodium thiocyanate - as I have been doing... what does this do also ?