If Epic monsters hit you 50% of the time, removing grazing hits would change much because they can graze you on a roll of 10 only (unless it changed but I wouldn't see why they'd do that).
Personally, what I would like to see changed with grazing hits is setting the damage at a fixed percentage (25% or 30% post-Heroic Durability sounds about right) rather than being based off the weapon's base damage. It'd make the character's avoidance much easier to calculate because the percentage is a known value, unlike the monster's base damage. It'd also prevent excessive grazes.