Maximizing Motes of Broken Time/Infinite Power grind in Legion Remix

When you hit 80, is it optimal to keep questing for motes or slam dungeons to get your ilvl up most efficiently?

I am currently at 28 Infinite Knowledge, stuck there because I am limited to LFR (I don't know how to get into a mythic+ and I definitley am not experienced enough to legitimately get into a group for them)

My goal is to eventually get to enough versatility where I can attempt a mythic+ on my own.