[I wonder if anybody understands the purpose of non-associative dimensions.]
Every dimension point references a point in space, even if it is an arbitrary point independent of any model or drafting element. If it is an arbitrary point, that arbitrary point should be relocatable. So my thought is dimension points which don't reference a construction/drafting element should have a sort of very visible, non-printing, built-in hotspot with a big + or x or whatever (look customisable by user) in their reference point, so that it can be relocated, and so that it is visually very obvious on screen when a given dimension point is referencing an 'arbitrary' point and not a model element.
I agree that once a dimension has been placed it is not easy to see which nodes are associated and which are not.
Of course you can tell by the cursor shape when placing a dimension but it is not so easy with an existing dimension.
However in version 21 (possibly earlier versions but I can't remember when this became a new feature) there is an option in the pet palette that allows you to 'move' a dimension node.
As soon as you start to use it you will see a square box at the dimension point if it is not associated (circle if it is), and you can move it to where ever you want.
If you drag it to an element node it will become associated.
This is much better than the old method of CTRL clicking to add a new node and then deleting the old one.
One of the forum moderators. Versions 6.5 to 25 Dell XPS- i7-6700 @ 3.4Ghz, 16GB ram, GeForce GTX 960 (2GB), Windows 10 Dell Precision 3510 - i7 6820HQ @ 2.70GHz, 16GB RAM, AMD FirePro W5130M, Windows 10