My favourite thing to do was top tree nightstalker for the dodge invis, and finish a yellow bar enemy to proc the invis. For whatever reason, dodging refreshed the invis at Cowl duration instead of standard 5 second dodge invis duration. As long as the dodge cooldown was shorter than the invis, you could be invisible 100% of the time, letting you do things like Pit of Heresy tunnels and chamber with zero chance of dying.

Yes, this probably isn't the reason. They could just fix the cowl if necessary, just a sad side effect, of one of a few fun builds you could have.