Remember, no ToB, so no maneuvers. This is a search for bonus damage through the core and Complete books only.
I'm not keen on a melee combatant built on the warlock's d6, so fighter has to be the majority of the classes, which means about Warlock-3 for 2d6 plus Practiced Spellcaster for another 2d6 when you can get to it. There's only so many stat points, so no use building up charisma and thus no use for Sicken et al. I see your point about EG when you get 2+ attacks, but there's 7 levels to wait for that with the warlock mixed in, and that's half the level life of most characters for me (we have never gone higher than 18th, and rarely above 12th).
It still seems more broadly applicable than sneak attack damage, which takes forever to build up through the feinting feats. What am I missing? Thanks.