if you are using a 90mm stem you either have freakish body proportions or are riding the wrong size frame.
Or you bought a bike supplied with a 90mm stem.
What stem length pro riders use is entirely up to them. It doesn’t make it right for me, you or anyone else. Frame geometry varies, so there’s no ‘one stem size fits all’ recipe, and what feels right on the brake hoods might not work so well when on the drops.
I’d suggest you fit the stem whichever way around suits you, there’s no need to flip it to a -veº angle because a bunch of forum pixels said so.