I think we deviated from the original topic...
I think dual coil would totally be doable, but not at a two single-coil performance of what we usually subject our RDA or RBA.
I usually run my RBA at about 10-12W. If true dual coil RBA were to be experienced, we need at least 20-24W (25 to be conservative).
With Provari's 15W limit, it would mean max of 7.5W per coil, which is generally where I vape my clearo...
Doable? Yes. Enjoyable? Depends. Making a coil glow is not a sign it'll work good. The coil gets quenched in juice and the amount that it can overcome the quenching of the juice depends on more power.
The only vv/vw mod that can do 20W is the DNA 20...
Would be cool if Provari did a 20W-30W mod in the future... The draw back of creating such mod is, making sure your customer doesn't use lesser battery with higher internal R.
Two batteries with the same discharge rating can have different internal R (you see it everyday even when you have the same make/brand/capacity battery, varies from unit to unit) but they will definitely heat up at different rate...
The advantage of integrated battery (in e-cig world) over replaceable, like in the Provari, is that the connection of the battery to the PCB is stronger (less resistive), when pulling 4 to 6A from a 3.7V cell, push contact and spring contact will start to not be an attractive solution...