First i would like to ask to make practice dummy more-enemy like, so storm totem can start attacking it. Would help a lot. I am guessing numbers in skill trees and cant test that out.
So issue. I had feeling storm totem wasnt affected by Minion spell damage, so i tested it in only way i could, that is storm crows. Their activated skill say “Minion, spell, lightning”.
Took down all gear, left only weapon with +220% Minion spell damage.
Used Crowstorm skill ten times, and wrote down damage number (all non-crit).
Result of 10 non-crit average hit: 4094 with 220% increased Minion spell damage
Result of 10 non-crit no gear hit: 4032
That makes 1,5% difference in damage.
Another small bug i noticed: In last chapter there was one quest saying it open idol slot, and it does not (i had normal slot layout (circle with blocked middle) opened before quest, after it doesnt changed, neither said quest reward.
Edit: after relog later i tried skill again - no gear yet - and it did around 1500 dmg (compared to 4k before). So i equipped weapon to see change. No change. I equipped all gear and didnt see any noticable change. I had to relog to see damage return to normal.