I disagree. I don't think you can just get to a point where you can kick back and let them roll in. If so, the same would go for talents and skills. If you were a master tennis player, and got to be the best in the world, then if you just stopped practicing you would slip up. I think lucid dreaming can get to a level where it is effortless, but that level is not permanent, you still need to practice.

I don't think it's possible to dream for over 90 minutes. Isn't that the length of the longest REM cycle?