You don't seem to understand something that is fundamentally important
No, I assure you I understand the source material.
The amulet blasts only appeared to be so powerful and of such great magnitude in DLOTS because Kun couldn't control it
Huge ridiculous unsupported assumption.
therefore the amulet blasts were working off of the amulet's power and not Kun's.
The narrator makes it clear that it is Kun's rage that "unleashes tremendous energies." So, to be technical, he powered it.
So anyone with common sence would know that when he would learn how to control them, he would be using his own power and not the amulet's and therefor the blasts would be completely different.
Except there's no reason to assume they'd suddenly become different nor does your theory of the amulet having power on its own hold any water.
The incident when he blasted Aleema with the amulet supports this.
Except he didn't use the same attack.
lol artifacts that were created through alchemy by the ancient sith ARE sith magic.
That'd be nice if that even was what sith alchemy was. Aww, look who doesn't know jack about the primary source material?
Sith alchemy was used to "shape and twist" the forms of living things, as DLotS makes clear.
Sith magic was an advanced usage of the Dark Side.