[oneeyedpigeon]

I think you're misunderstanding the question — possibly for comedic effect (?), it's hard to tell.

"zeroes" is the plural form of the noun "zero", yes. But the question is about using the form "zero" as an adjective and how that should affect the plurality of the noun it applies to: "zero book(s)", for example.

[powerhugs]

I am not trying to be funny. It seems to me that you are misunderstanding the usage of the word zero in this context, as in absence of any. Synonymous to "no", as in "no threes".

It is not about the number 0.

[oneeyedpigeon]

OK, if you think I'm the one misunderstanding the question, can you explain how?

The example in the question is:

> For example, if we choose two 2s, zero 3s, and one 5

That's talking about "zero 3s", not "three zeroes".

[powerhugs]

> That's talking about "zero 3s", not "three zeroes".

In this context "zero" is not a noun, but an adjective.

[powerhugs]

I was too quick to press post, and I updated my above comment after you replied to it.

In addition, see the adj. definition of zero: https://www.oed.com/dictionary/zero_n?tl=true#1209971660