Blender Version
Broken: 2.82
Worked: Since Ngons Feature

Short description of error
When you have a single edge that's not connected to a face, you can subdivide it (inserting vertices) with Loop Cut (Ctrl+R),
this shows a yellow dot/gizmos that shows you where the vertices are being inserted and how many,
when you try to do this when an edge is part of a face, you can still insert a vertex and many vertices, but it doesn't show the yellow dot.

(I know the Ctrl+R tool is called Loop Cut, but it would be nice if depending on your selection mode, you can insert vertices, add edge loops, or subdivide faces with it.)

Exact steps for others to reproduce the error

• Open Attached file
• Loop Cut (Ctrl R) on the loose edge (See the dots)
• Loop Cut (Ctrl R) on an NGon edge (where are the dots?)