I was going to brew an Extol Substitute to see what I would get but reading various posts I see prepackaged Extol has a part B. My formula from Jacks Chemistry Pages does not have a part B.

Is part B of the Kodak product ment to be added at the time of brewing because if it were packaged as a single unit it would have an adverse reaction in the dry form, but if mixing from scratch for (near) immediate use, all ingredients may be mixed at the same time?

TIA