Do you need to know full ring to play 6-max?

[B00T]

Situation:

I have a friend who has played NL HU matches a ton. For arguements sake they understand poker concepts and theories. They want to get into Limit but find full boring, and like the idea of 6max better.

Without any limit experience do you think it is bad to just hop into and learn 6-max with no full ring experience? Essentially they would be learning limit poker and gaining experience which they need no matter what, but how much is lost at not playing full ring. They have the bankroll to take a $1000 hit at 1-2 6max this is strictly about learning. He is going to take his limit learning lumps regardless.

The major question is: If you want to specialize in 6-max and your "dream is to work up to 10-20" do you ever need to set foot in full ring?