shaggs

G'day Therrin
Haven't used on like you have in the pic. Only a normal rappel rack for abseiling etc. Like you said, you rig from the bottom up. Ie if you have a five bar rack and only rig three bars for your size then start from the bottom. In theory that way you can add wraps whilst on rope. I haven't actually done this myself but I assume there is a practised technique to this.
They are a good device. Inline anything definately beats twisting eights.
Any pic of he device in action??
Cheers