Elemental Synergies gives your Fire/Ice/Thunder skills +1% damage per skills with the same element on your bar, per perk rank. The bonus gets doubled.
That sounds like a pretty large boost… but then due to a bug, Permafrost straight up gives you +18% damage just for having an ice skill equipped. Plus, due to damage buckets, flat bonus % damage isn’t that great.
So that leads to every build basically just using a cookie cutter template of the best attacks from each element. If you go through the tier lists, every major sorcerer build is using Ice Blades and Teleport in their enchantment slots. Then for the Enlightenment stacks, you’re hotbar is taken up by: Ice Blades, Teleport, Ice Armor, or Flame Shield.
Leaving only 2~3 slots for the elemental ultimate + main dps skill your build is using.
If Elemental Synergies were stronger, then you would have a reason to fill your entire hotbar with terrible, but thematic, skills of the same element.
I think it should have three extra passives branching off Elemental Synergies.
All three passives would be identical, but based on the different elements.
Something like:
Fire Mastery: Whenever you cast a FIRE skill, you get an elemental stack that increase your Pyromancy Attack Speed by X% (max of 10 stacks). Whenever you cast a non-FIRE skill, your stack resets.
Ice Mastery: Whenever you cast a ICE skill, you get an elemental stack that increase your Vulnerability Damage by X% (max of 10 stacks). Whenever you cast a non-ICE skill, your stack resets.
Shock Mastery: Whenever you cast a Shock skill, you get an elemental stack that increase your Shock Critical Strike Damage by X% (max of 10 stacks). Whenever you cast a non-SHOCK skill, your stack resets.
That would help lift up other Sorcerer builds by adding bonus to different buckets