"just a tad confusing" as there is only one route allowed, thru
What is more disturbing is that neither The ACMUX input nor the BMUX show when shift-clicked any valid connection though the list of valid connections is not empty.
That should / could be corrected.
To make a screenshot of the suggested connections is not easy, but holing down the shift-key as long as possible (when clicking on other items on the desktop) could solve that problem.
That could be corrected as well.
Sorry, forgot: To make clear I am talking about a SCBLK-module.