A new strategy has been found in Underrot which allows players to start on the last boss in Mythic+, possibly opening up some new routes.
How to Start on the Last Boss of Underrot
Streamer nadasswow has shown off some new tech in Mythic+ Underrot, allowing players to start on the final boss of the dungeon.
The steps to reproduce this seem to be:
Clear to the end of the dungeon on M0.
Everyone jumps into the final transport section at the same time.