Spirit Wisp Amulet not working with Engineer's skill

[StratOFerus]

Title is self-explanatory. Engineer's skills don't work the same way as other skills in terms of cooldown, but I had expected that with Spirit Wisp Amulet, I'd get ammo onto the heavy weapon. Apparently, nothing happens.

Would be nice if it did though. Looking at you, devs and whoever in the team looks at this.