Back in 2.0.0.c I reported DoT duration increase mechanics didn't impact poison duration and testing a flame build today (Season of the Inferno patch), I see DoT duration mechanics still not working. Character sheet says 'Bonus DOT duration to skill' is +5' (5 what? seconds I hope) and I have a Volkite Psalm for 100% more DoT duration but all Heavy flamer DoT's still fall off after 3 seconds.
Either I don't understand the mechanic or I believe this is bugged. Wouldn't a single socket'd Volkite Psalm make flame Dot's change from a 3 second duration to 6? Do the Psalm have to be in the weapon itself to increase duration or may it be in any item? I will test some more.