Könntest Du uns sagen, wie Du im ersten Satz commodity time übersetzen willst? Das hat wohl Auswirkungen auf Deine Anfrage.

Gemeint ist offenbar, dass dann, solange ein Teil der Arbeitskräfte( einschließlich der checkers) nach commodity time bezahlt wird, dies auch für die anderen Arbeiter gilt.

Parsing: "any portion of labor ...including checkers" - " working commodity( time)" - "all are listed as commodity (time workers)"

As to what was probably the intended meaning, I agree with #1. I read the sentence as defective, and suspect that the intent was to write,

For the period of time that any portion of the workers, with "workers" understood to include checkers, are working on commodity time [=with a commodity], all of them are to be listed as on commodity time.

But if this is a contract, it would be wise to ask to make sure, because the language is defective.

BTW, I would understand commodity here to mean cargo consisting of one specific good. I think the timekeeper is probably required to log the time the workers spend working with each specific commodity, rather than just time spent working with any of the cargo. Here, the entire team is always logged as on commodity time if any of them are (already or still) working with the cargo in question.

Das scheint aus einem "Performance Work Statement" über u.a. die Entladung von Schiffen in japanischen Häfen zu stammen ... und wurde möglicherweise aus dem Japanischen übersetzt oder von einem Japanischsprecher verfasst ...

https://www.google.de/books/edition/Decisions...

(Compilation of US National Labor Relations Board decisions from 1960)

We note that the difference between tally clerks and checkers and the timekeepers herein involved is that the clerks and checkers check cargo to and from ships, while time-keepers keep longshore time, i.e. hours worked by longshoremen, and commodity time, i.e. a record of time spent by longshoremen loading or unloading a specific commodity or doing some other work. 

Superfund! Das glossary of terms dürfte für Übersetzer höchst wertvoll sein.