PoE Templar, Arcane builds similar to My Thunderquiver Merc vs Uber Maven

Yo I made a build and am feeling too lazy to make a video for it. Here's the POB. it can do exarch/eater/sirus/maven/all invitations deathless. tanky and great aoe boss damage, clear isn't the best but it's not the worst. I think furthest I got in simulacrum was 26 or so, but ya know mod rng and stuff and I attempted a total of 2 I believe (I haven't played in a few weeks). Idk feel free to ask questions but I might not remember. no idea what the gear is worth, I think I made everything besides the boots. gl

Path of Building question... as I scrolled past the "Precision" notable on the skill tree I noticed a huge bump in DPS which caught my eye. Was a bit surprised though because I am playing as a manabond hiero with cyclone + arc, so really spell based. I don't recall global accuracy being meaningful to spells. This notable plus the minor before give +10% cast speed as well but was skeptical that addition would result in \~13M+ additional damage. From what I can tell the trigger rate for manabond increases resulting in the higher dps. As a comparable test I added +10% cast speed on a dummy tes