Hi I've found a way to get up on the mage place in IF
First you shuld get up here and use Blink or Autounstuck!
When you got inside the mountain you shuld get to this spot and use rocketboots + slowfall and jump to the arrows direction(not mine, im facing a little bit to much to the right.)
If you did it right you shuld soon be ontop of the mage place. Gz!