Hello,
I can't detect the spell charges of Arcane Blast with that addon. I tried to highlight trinkets when 3 Stacks of Arcane Blast are there but it dosn't get triggered. I tried to detect this as

• Buff
• Debuff
• Spell charge (think this is the right one)
• Spell Time Remaining
  The Condition never gets satisfied. I'm using the german client, but other spells are working so this seams to be no problem.

kind regards

For some reason, this counts as a deubff on yourself.

So you need to make a condition for Debuff Stacks, with the unit of 'you', and the spell 'Arcane Blast'.

I just tested this. I guess it's a debuff because it increases the mana cost, despite also increasing damage.