[Nosedagger]

Kiedo brought this to attention some time ago with the discovery of Lunge Tap (serious here). Lunge Tap is reverse elunge + stab. If all goes well, the stab will give the target a massive(a la Block Tap), and as the target throws the massive, the lunge will hit the target, thus instafall (Massive Fall in daggerspeak). Even if the target does not react as intended, the reverse elunge will send you flying away from the enemy, so if you want to stay safe and try for an instafall without the risk of getting PB'd, Lunge Tap is one of your better choices.

I suppose that forward elunge isn't used in Lunge Tap because you'll overshoot further, and you'll still want to be relatively close enough to drop in a few shots if the insta works. Sideways elunge is hard to aim. Besides, reverse elunge looks the coolest.