Nope. The universe 'notices', by reacting in exactly the way you'd expect if relativity was happening.

That last bit - "...we can't even know.." is sophistry.

There is nothing sophistic about this argument. It's pretty obvious.

This is why some people argue that we might be living in a simulation. Because we don't have direct (not mediated by our senses) access to the underlying reality.

True about everything, including relativity. Can't have the argument without assuming it.

The fact is, the universe operates consistent with Relativity.