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?