WoW Classic Fresh - LBRS mage boost - 120 mobs, 41k exp/run, 13min runs
LBRS boost, lvls 45-60, ~42k exp/run
The other spot boosties can get exp from is on the ledge to the right of the UBRS door. They can get there w/ an invis pot or you can pull all the mobs in the first room before running to start the pull.
Videos I copied:
Best wow player to ever exist - https://www.bilibili.com/video/BV1fJ6...
Guy w/ only wand - https://www.bilibili.com/video/BV1wsC...