Parameterized Skadis Universal ring holder

I started off with ripetomatofetish's great round holder for the universal Ikea Skadis hooks. However I was missing a little bit of offset between the ring and the baseplate. In the end I did a major overhaul and added a number of parameters to easily adapt it to different needs.

Requires one Skadis_Universal_Hook from CSD Salzburg's IKEA SKADIS Universal Hook Set.
No support needed.

New features include:

Parametric distance between ring and base
Parametric height to decouple ring thickness from ring height
Parametric cutout at the front of the ring (Handy for things that won't fit through the ring from the top, like my chisels)
curved part of the connector scales together with the ring height to give a better visual impression
in case the ring height gets too big, the curvature of the connector is minimized to prevent obstruction of the mounting hole
added assertions to check parameters for plausibility, i.e. you're not allowed to block the mounting hole by a ring being too high
moved all user-modifiable parameters to the top for improved convenience