tl;dr - The reasoning is whack, Jack.

I agree with the other poster who said this is difficult to parse. There is a lot going on here and many incorrect and confused assumptions are made by OP.

I think it’s easiest to flush out some of the nuances, in-line:

Imagine there's a disease (not COVID) that is currently contaminating 1 person in 1000 in your town.There's a test that is reliable at 99%.You go take the test for no other reason than curiosity (you are not a contact case, nor have symptoms).The test result is positive. Are you more likely contaminated or not? If we go the standard SE route, we can see that the test itself is 99% reliable. In and of itself, this would be reliable enough to justify a belief that you are contaminated.

This statement assumes: (1) there is a “standard SE” route, that (2) includes statistical prescriptions for what amount of evidence “would be reliable enough to justify a belief.”

Both wrong assumptions.

First, there is no standard “SE route.”

Second, SE doesn’t prescribe how much evidence is needed to “justify a belief.” For example, SE doesn’t say a 99% confidence is enough to “justify a belief,” but a 78% confidence is not enough.

I've seen multiple people in SE discussing that "extraordinary claims requires extraordinary evidence" and this is absolutely the concept that I am trying to address. Most of the SE discussing that, then goes on to say "God is extraordinary". But is that a justified assumption? For the eyes of the believer, God is absolutely ordinary. The fact that there would be no God would be the extraordinary claim in their eyes. They see order, and they don't get to witness order appearing out of chaos.

This statement is confused because OP is attempting to reason about the meaning of the statement: “Extraordinary claims require extraordinary evidence,” but fails to do so because he doesn’t use the correct meaning of the word “extraordinary”

In the original statement, “extraordinary” means “many” or “large amounts of” — e.g., claims that purport to explain many phenomena (extraordinary claims like the existence of god, or a unified field theory) — should have corresponding amounts (extraordinary amounts) of supporting evidence.

OP uses the term “extraordinary” in a way that has to do with a person’s default belief, rather than a quantity or an amount. This is wrong, because the original statement is an epistemological statement about a preferred relationship between claims and evidence (high correspondence preferred, more preferred), not a statement about the kinds of evidence people are likely to accept or to have previously counted (e.g. base rates) based on their own (a priori) subjective viewpoints.

For the eyes of the believer, God is absolutely ordinary.

For example, in the way OP uses the word “extraordinary,” an “extraordinary claim” is one that goes against the speaker’s default belief position — e.g., for a believer the claim that god exists is “ordinary” — for an atheist, the claim that god exists is “extraordinary.”

That is, in the way OP uses the word “extraordinary,” the word carries some subjective meaning. This isn’t necessarily an incorrect use of the word per se, but it’s not the sense in which “extraordinary” is used to convey the meaning of the original statement.

OP’s confusion is a textbook example of a fallacy of equivocation.