Right now there is virtually no support for these, so even calculations that specifically apply to triggered spells/attacks don't apply (e.g. Mjolner's +100% spell damage to triggered spells or Discharge's trigger penalty).
Optimally, the DPS of skills that trigger other skills should be broken down into trigger DPS and combined payload DPS, so that you could optimize for the payload DPS in particular (not DPS of particular skills in the payload).
Extra caution should be exercised with respect to the interaction of cooldowns and the server tick rate as it is the primary determinant of the payload proc speed.
Additionally, the trigger rate / cooldown times aren't respected in PoB right now. If I'm using Vengeance then PoB will still say attack speed boosts my damage when it plainly doesn't because there's a hard cooldown time. On the tree I can thankfully sort for Average Hit to find my best nodes in that case, but it's still quite clunky.
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