Help with Explosive Arrow and Additional Arrow mod

Hi!
Could you tell me - does the additional arrow mod on quivers helps you stack 4 fuses of Explosive Arrow with just 2 attacks ?
I'm not sure because as far as I know the ignite comes from the highest hit with fire damage. So if you hit 2 monsters in a pack with two different arrows, there are 2 equivelent explosions, so the highest fire damage for the burn to start will be the same as just from one arrow ?

No, you will still need to attack an enemy 4 times to stack 4 fuses.

If you got two enemies standing side by side with 4 fuses each, they will be caught in the explosions and hit twice each, giving you two rolls on chance to ignite and also two damage rolls so you will have a better chance overall to score a good ignite.