Hello, I’ve tested dual wielding the Undisputed axe Undisputed - Unique Dragonbone Axe - One-Handed Axe - Last Epoch Item Database
and the 5% increased physical damage for each recent melee hit against a bleeding enemy (up to 255%) effect does not apply twice. Hitting once only gives a 5% increase. I got told by the community that dual wielding uniques should give the effect twice, unless stated otherwise