Closest thing we have to it now is Horrid Ignition, but that's locked to Fire. Wish we had more of the "spend an extra action to add a rider effect to your blast" kind of impulses.
Yeah Fire's damage is horrendous, but it does have options for increasing allies' damage, and their own.
Furnace Form and Ignite the Sun can eventually give themselves +2d6 fire damage on their blasts, for a Sustain and two rounds worth of buffing up. Kindle Inner Flames would be some more buffing, for another round of setup, but sadly doesn't add the +1d6 fire damage to more than one strike each.
That said even if Kindle Inner Flames did provide +1d6 fire damage to every strike three rounds of buffing and not really striking much if at all is a bit much. That said it might be worth it for a Dedicated Gate if Stoke Element provided a Status bonus to the +1d6 fire damage each of these provided and lasted for the full duration of the buff so the +1d6 fire becomes +1d6+5(+10 for Ignite the Sun) and thus combining each with a Stoke Element on the round before, though that would then mean at least 4 rounds, allowing a Dedicated Fire Gate to provide allies with +2d6+15 fire and themselves +3d6+20 fire for the combat, whatever may possibly be left after 4 rounds of buffing.
That is kind of how the Legendary Kineticist did it. Though their Blast was more of a Con based Cantrip that scaled by 1d6 every other level, for most elements though the more variable earth used d4s and there was a feat for Blue Fire that used d8s.
It was a single action Cantrip with Flourish so you couldn't spam it a bunch in one round, and then they gained Infusions that cost an action to alter the blast, though in that version the blasts were also Focus point using abilities and would require spending either yet another action to Gather Power to avoid the Focus Point cost or use a Free Action to Burn and take Stunned +2 to avoid the Focus Point cost, so again an action cost.
Now I am not really for the whole Focus Point thing, but I do like the idea of using extra actions to alter a blast. Though I would prefer more of a cantrip damage blast for that than a strike damage blast. Though a strike with enough runes could add up some damage.
Some people talk about the Legendary Kineticist being overtuned or too powerful but I don't see it since they can go all out to do 10d6 in an area, something the current version can do as well with the highest level abilities.