So if an actual creature existed on a planet 100 billion light years away, they would have to be a human construct?
Since such a thing is "unknowable" then any attributes assumed, like "existance" and 100 billion ly, are in fact the constructs of a very specific human. You.
IF this Deity exists, it exists regardless of our beliefs, perceptions, logic, or ability to frame an issue. And if not, then not. Period.
Again, since attribues are assigned, such as "unknowable", "exists" and "creator" all without evidence then these attributes, and the god to which they refer, cannot be refered to as other than constructs of the human imagination.