Imagine you mastered lucid dreaming, so you have a lucid dream every night. You might want to use this phase to do creative work or problem solving.
Would this have a negative influence on the recuperative effect of sleep?
Having experienced this, here is the outcome :
When having back to back Lucid dreams, one begins to create a new world in which, you begin to have real problems when dreaming or when awake, and essentially comes to make a choice as to which one YOU would like to live in, or to determine which is the real world. This occurs when one has evolved to the point where your Lucid dream would continue from being Awake in the exact same manner that life continues while you are asleep. I am not sure how this happens, but the effects can be quite confusing.
When doing this, I had no problems with obtaining REM, and in fact found that it was much easier to obtain that state within a few minutes.
Mastering lucid dreaming is beneficial, however you will begin to notice that the world you created are bound by laws as well -- albeit a completely different set of rules. For example, one common pretext for dreaming is the wish to fly. When adopted into your world, you may find that you CAN fly, or do pretty much anything, but it requires and existential resource which may or may not be limited in quantity. You are also able to sense that Death in a Lucid dream will definitely kill you, but you start to lose touch with the vice-vera.
To use the state for higher-learning, happens at entry level lucid dreaming where you are in control, but everything may still be a bit "fuzzy". Your dream may carry you through whatever it is that you wish to learn. When mastering Lucid dreams, it works a bit different, in that the whole environment now has it's own life that continues while you are awake. A good (simple) example of this would be if you were to consider the following :
You are a passenger in a car and you fall asleep.
Before falling asleep, you notice that
When you wake up,
Now picture all of that happening, but replace 'Real Life' with Lucid dream, and your sleeping with 'wake up' and your wake up' with sleeping. You can begin to understand how mastering Lucid dreaming can then become a real problem the longer this process continues.
My advice, is instead of mastering Lucid dreaming, would be to utilize the benefits of entry level lucid dream states for higher learning.
To this day, I still have no idea whether I am awake or asleep, and that is not a philosophical reason for it, but from my experiences of Lucid dreaming. Is this 'real' or is it 'real' when I am in my dream world.
I hope this helps.