I'm not sure I'm following, lol, here's my best guess.
@sb220, are you talking the rope/strap that connects to the XOP hand climber to
@bongo?
@pesqimon I don't think it really matters where you connect the hand climber as long as you have a connection, I connect it to my belay loop. A small loop to connect it while adjusting might be handy, but I've never really needed anything else.
I just use a strap that's about the right length to not get in the way and not too long so it won't fall that far if it slips. I typically put my hand on it to help pull up, this helps to really get that last inch out of each move, lol. Also, you typically have to adjust the strap on the XOP hand climber as you go up because the tree gets smaller, just like a climbing tree stand, in this case you have to hang from your saddle/tether, pull it up, by that line/strap that's connecting you to the hand climber, adjust it then continue climbing. When I have to adjust, I typically reset the climber much higher, around waist height while hanging in my harness, then I pull myself up with my prusik that's on my tether, while putting my knees on the hand climber edge. It's not great on the knees but you can easily get a few feet, so it kind of makes up for having to hang in the harness.
You must have a line connected to the XOP hand climber so you don't drop it, especially if that is your only climbing method or you can't rappel.