The Combuster is often chosen over the Fang of Vog as the weapon of choice when it comes to dealing elemental damage and fire status
But first lets look at how these weapons are used
Both have a 3 strike combo (although the FOV is slow it can easily be mitigated with any ASI item or pet perk)
The Combuster deals more damage and is faster making it the better choice when it comes to the regular attack
The Combuster's charge is designed for being fired into a swarm of monsters that are chasing you, dealing great damage spread and knockback.
This charge attack is best supplemented by vortex bombs, gunfire (with minimal knockback), Venom veilers and Voltaic tempest, as well as other status brandish lines
The Fang of Vog charge is very useful but only in the right circumstances
Immobile, large, and cornered enemies are the best targets of the FOV charge
A good teammate will communicate with the FOV user to make the most of charge attack. This means Cornering regular sized monsters with sword combos, pulsars and blast bombs. In addition, poisoning stationary monsters (polyps, pups, howlitzers, battlepods) can be devastating. If cornering monsters is hard try freezing them, this should allow your partner for move into a position to do the most damage.
The other reason people never get the FOV is the drawback of the devastating charge. It is best to treat your remedy capsules and health capsules as "ammo" for your fang of vog charges. As you use these up to recover your must be increasingly careful with your charges.
As far as battle sprites go the drakon is useless to the FOV charge as both inflict fire, the maskeraith is useful to have as a teammate's sprite so long as they are consistent about recognizing your targets and poisoning them, the Seraphynx is a godsend for any player that enjoys spamming those charge attacks as the heart drop increase it gives helps the player survive an unlucky charge.
In teams with little coordination using the FOV charge can be dangerous as you may release your charge on a monster only to find it has been pulsared elsewhere and you are left in pain with nothing to show for it. The combuster is the best choice for situations like this where you can attack at will without having to worry about weapon backfire.
I agree with your points, including your emphasis on FoV's charge. But here are three suggestions.
Yes, FoV is slower than Combuster. Yes, you can speed up FoV using ASI. But ASI would also speed up Combuster. Your text suggests that ASI lessens the speed difference between the two, when all it really does is shift the speed difference to a higher level.
You don't mention that FoV's regular attacks can ignite monsters. That's definitely a mitigating factor in FoV's favor.
Some of your sentences lack punctuation. Fix them. If your presentation is sloppy, readers may infer that your thinking is sloppy, even if it's really good.