https://youtu.be/ZBOfQPBjtIM?list=PL8f-9msyKA2zR9gqfRf_v11qHvT30DQ2z
I really don't know enough about this skip - more research and understanding would be required - but effectively i believe around half way into the auto scroller (when you have to get off the boat) you can make your way around the level and get out of bounds, and then make your way to the area that is the end of the level - and finish the level without having to sit on the on the lava boat.
based on my understanding completing this would be able to save a further 3-5 minutes.