Impending Doom Support

I am fine with this skill having an internal cooldown (0.15 sec) but wish that doom blast does not have 3 uses limit.

Impending Doom in Forbidden Shako doesn't work if there is predator support

https://imgur.com/a/9F6xuav

when i socketed curse skill on it i got signal prey but no doom blast.
is it intended or not?

Possible idea: the damage type of impending doom should be determined by the curse skill which is linked to.

Did some experimentation with this:

The gem description is missing the radius of 'Doomblast'.

And using it has issues. Issues due to the global cooldown. I dont think this global cooldown is a good mechanic. Cooldown per monster would be better mechanic.
If I cast curse (with cursed ground + echo for example) it can "fizzle" (do no damage) due to there being no charges due to some random mobs somewhere else (not even on my screen) triggering it. Unfortunately this leads to unreliable gameplay.
And in general even if it "works" it will still be some random(?) max 3 mobs that trigger explosions. Its not like proper skills like KB or elehit that will reliably cause explosions from everything they hit.

And as its now the damage potential seems to be a bit low. Its the main reason I stopped experimentation.