Just reading over it, it looks like it is a height of the chain, but is it the ring radius? the default is 139, which lo.oks like the ring radius. I think the the value in my system is wrong at 92, but I wanted to ask.
Is “vertical” with respect to the floor (+ 15 degrees) or the Z axis (-75 degrees)? Technically neither are vertical, but they are perpendicular to some surface… (asking for a friend ;))
EDIT: kind of like this (picture lifted from another post - arrows added)