My beef is with the argument in the op, atheism pretending that it is simply the position of uncertainty. Sure we can be uncertain either way, that's what makes leaning either way a belief, not a certain claim (outside of strong/gnostic (a)theism). The original gumball argument pretends that uncertainty about odd vs even is the atheist position, but that's uncertainty, agnosticism. The only way to properly, non fallaciously use the example is full vs empty, because atheism is nor arguing over what gods exist, but that it's unlikely any of them do.
Atheism, by definition, is only focused on "belief", e.g.
"I don't believe in god (or gods)", so it is not about "knowing", which are the focus of gnostic and agnostic positions.
But we are humans, so we are far more complex, so we are often cannot be defined by one definition or one label.
Hence, an atheist can be gnostic atheist or agnostic atheist. And the same can be applied to gnostic theist or agnostic theist.
I have no problem with atheists being
gnostic or
agnostic atheists, or with atheists being just "atheist". My problems are with your unfair and over-simplified analogy, and that you would call "atheists"
liars, just because they don't fit into what "you" think any atheist should be.
And when atheists do respond to you, instead of learning from what their own positions are, you immediately tried to put the badge of "dishonesty" label on them, without considering what they have to say.
You say this...
I'm simply interested in honesty, honest positions and honest discussion.
...but given that you don't give consideration to what atheists have to honestly say or you ignoring what they are saying, then you are really not interested in
honest discussion after all.