First, tell your friend that he shouldn't punish himself with these stupid imperial units. (Don't tell him that stupid metric units don't make anything easier.)
Then, tell him that it's an unfortunate historical bad habit of the SMF folks that they call this you-know-which wine preservative “metabisulfa
te” rather than “metabisulfi
te” (though, again, the label on the bag doesn't change the properties of the product).
Leaving out the thiosulfate from ZCS means you're on your own, and you have to validate every step anew, without reassurance and backing from @Todd Ziegler
et al. Enter JCS (John's Colour Stabiliser)
This new uncertainty includes first and foremost the JCS dosage. For ZCS it was found appropriate to use it 1:1 to the FO.
Now we have to guess how much 32 fl. oz of your FO weigh. Let's assume 1 kg for now.
The Lazy John recipe (without thiosulfate) calls for 3 parts sodium metabisulfite per 10 parts water.
JCS target batch: 1 kg = 13 parts
Water: 10 parts = 10/13 kg = 769 g
Sodium metabisulfite: 3 parts = 3/13 kg = 231 g
(Per kg of the original ZCS recipe with thiosulfate, you'd need 10/16 = 625 g water and 3/16 = 188 g of the two sulfuric salts.)
So he is a little dense.)
Yes. Density is the reason why we prefer weights over volumetric measurements whenever possible. Including VCS, which is most likely denser than the FO in question, i. e. will have a smaller volume for the 1:1 dosage.
Why so angry? Wasn't this your business just as well? Or have you grown out of that phase?