Drain ailments wont work with Despair + Burning Inscription, while switf affliction does.

Swift Affliction: Supports any skill that deals damage, causing it to deal more damage over time but have a shorter duration.

Drain Ailments: Supports Spells that deal non-Ailment damage over time, causing them to consume Ailments on enemies it applies damage over time Debuffs to in order to deal substantially more damage over time.

Yet somehow only swift affliction supports Despair (and probably other curses as well) when linked to Burning Inscription.

But even more interesting is that none of them support Decaying Hex? Is there a particular reason to limit players ability to use curses as main damage skills?