And on you go with the straw man. The term was "absolute totality of all existence". To which you produced a straw man twist and redefined it as "absolute totality of all 'known' existence".Something can exist outside of the absolute totality of all ("known" existence) and beyond the *constraints of our universe. YES
You see the question is flawed to begin with.
When you ask that question it can only be applied to the observable universe. But we have already accepted the universe is larger than the observable part. So you have already accepted that something exists outside of all known existence, you just add the unknown to our universe. Now you have to accept there maybe a beyond this. Or... Maybe you should just stick with your classical view of the universe, after all no one said it wasn't crazy to imagine this. But it is valid science and in the minds of many who care to venture there.
Due to your twisting of the question I proposed I will ask you again, and be even more specific:
Do you consider that something can exists outside of the absolute totality of all existence (known and unknown)? YES OR NO?