Has anyone here achieved one before and does it have much carryover to any other skills or exercises? I was thinking that it may have a lot of carryover to the iron cross since it seems to work on shoulder adduction, but I'm not entirely sure how much carryover there is between the two. I think I feel my triceps long head the hardest when I attempt these. What difficulty score would you give this skill and how long do you think it will take to attain this in full lay?
I haven't really started training for this yet, but I'm thinking about starting soon since I can't work on crosses yet because I only can hang my rings on a doorway chin-up bar and because it's a pretty beastly looking skill. This is different from the one arm front lever where you have your body tilted more upwards instead of to the side. Also, feel free to discuss anything about this skill.
A pic:

EDIT: The 'one arm side lever' I was talking about is actually a variation of a one arm front lever and not a side lever which I originally thought it was.