The Gs are modeled, that is what the blackout is. What would be nice is some audible that let you know that you were on or passing the fully blacked out point.
There are times where I am in a turn and going in and out of the black out, then at some point my pilot stays blacked out, if I knew I was close to this threshold I could ease up a bit.
Some games add a pilot groan type of indfication.