I think ACT is still having problems calculating flamethrower. Plus, I also don't think it's tracking self buffs all that great yet.
Flamethrower is such a minor part of the damage, that even if it's tracking it wrong I don't think that has a major effect.
or maybe I'm still playing completely wrong.
Flamethrower is 60 potency per second, cancels your autoattacks reducing its effective potency per second, and is generally used as a button to help you overheat on time. It's not really a factor and certainly isn't anywhere near enough to make up the gap even adding it in for full duration on CD. IIRC ACT continues its proud tradition of not properly calculating Wildfire damage, but at least Aiurily was going back and manually factoring that in to the overall calculation. And Aiurily popped up to discuss things pointing out that the method used to derive the numbers was ultimately going to
overstate MCH's damage due to ending right after a burst window.
ACT is going to lose the ability to track a lot of things due to the changes made to the combat system; data that used to appear in the combat log flat out doesn't anymore, which is going to be a limiting factor. But at least for NA numbers, I know part of what was done involved using known quantity SSS dummies from HW to check damage and they seem to align fairly well with the JP list.
It's just HW launch again; they'll get around to buffing it most likely at some point, but they're not going to breathe new life into the job because it's incredibly likely that once they get around to it people will have moved on. If they're going to keep rebooting the job until it gets mass adoption, they likely need to stop botching the launch.