Which custom editor tool to make empty gameobjects selectable in scene view?

Hey community,

I'm looking for a good way to make empty GameObjects selectable in the scene view. I'm building a sort of graph with waypoints, where a Transform defines a position in space, I also have edges between them. None of my components actually need to be rendered, so I only want Handles/Gizmos in the scene view to position and connect them.

Right now I'm using OnDrawGizmos and rendering lines, as well as wirespheres, but I can only select the empty GameObjects when I click very close to the center of it, which is hard sometimes.

Is there some sort of Gizmos or Handle which can be shown and selectable for my points? I basically want the Gismos.DrawWirSphere() to show and be selectable (then maybe turn yellow), but it doesn't seem to work that way by default.

The Handles class also only shows when the object is already selected, so not helpful in this case.

Even more simply phrased: I want to draw a selectable fake object in the scene view with a custom size and changing colors.

Also, I want a solution that doesn't require runtime code in my game, so drawing a mesh during EditorTime and then disabling it when the actual game starts, would be a lot of wasted resources in my case.

Thanks in advance!