In light of the current Blade of Woe synergy bug, I'd like to bring attention back to a long-time Blade of Woe problem and propose a simple fix for the development team.
PROBLEM: The Blade of Woe and vampire feeding are bound to the same key, and which action occurs depends on the distance to the target. Also (on console at least, not sure about PC), synergies are triggered by pressing two buttons simultaneously and sometimes an ability fires instead of the desired synergy. This causes numerous obvious problems during Dark Brotherhood assassination missions.
SOLUTION: When in the crouched position, disable emotes. While crouched, replace the emote wheel with a crouch-action wheel, allowing the player to toggle between pickpocket, feed, and BoW. Bind the chosen action to A. When crouched, pressing A will perform the currently-selected crouch action.
This is a quick and easy fix to an annoying problem, a simple QoL improvement that will take little effort to implement and greatly improve the experience for vampire assassins.