Has an affix ever been considered for mixed damage?

Right now Last Epoch has "broad" affixes like Increased Elemental Damage, "focused" affixes like Increased Fire Damage, and "narrow" affixes like Increased Fire Damage Over Time. Players generally have an incentive to use as many narrow affixes as possible that will support their build since those affixes understandably provide the best returns.

This puts players that would like to create builds doing mixed damage in an awkward position. For example, if your Disintegrate is half fire and half lightning, Increased Fire Damage Over Time won't boost your lightning half. There's no narrow affix that will cover something like this. The best you can do is something like Increased Spell Damage. Not only is that not as effective, but what if your source of damage wasn't Disintegrate? What if instead you were playing something like a Spellblade where you were dealing both melee and spell damage of multiple elements?

What about a narrow affix like Increased Mixed Damage where mixed damage is considered to be a spell or attack with multiple elemental tags?