I wasn’t trying to be offensive.
You said "So I would think discussing what God is or isn't would be a critical part of both theism and atheism." As an atheist I was saying that, imo, discussing what god is or isn’t would be the same as discussing whether or not a unicorn has a spiral on it’s horn, because we have no evidence that unicorns or gods exist and no scientifically theoretical basis to posit that either should or might exist - unlike something like black holes, which were predicted by Einstein’s theories, so scientists went looking for them to see if those predictions were correct or not.
By and large science doesn’t start with definitions, it starts with evidence, unexplained phenomena, theoretical frameworks, etc. So postulating vast intelligences that can do…something…because the universe is big and old - hasn’t really got any meat on its bones for science to sink its teeth into.
There’s a quote from a famous science fiction writer, Arthur C. Clarke, called Clarke’s First Law - "Any sufficiently advanced technology is indistinguishable from magic." Or from gods. If you want to redefine god as something very intelligent that can do things beyond our current comprehension, but is within this universe and is mortal, then you’re probably just defining an advanced technology.
Anyway, I wasn’t disputing your right to a personal definition of a God, but most atheists that I know don’t think making or discussing such a definition is integral to their lack of belief. Real phenomena/evidence is what would get most of us to pay attention, not a definition.