Altered Time - your #1 World of Warcraft Mage resource!

Hello all, I play arcane mage, presently mythic Uldir progression with gear iLvl 378. I have tailoring as a profession and have crafted 385 Emblazoned Deep Sea Breeches in my leg slot. The stats are 140 Crit and 105 Mastery. My question is - what would be considered the best stats to roll for as Arc...