I’d recommend this thread as it seems to be trying to achieve the same end using aliases. Note though that aliases can have their own links, discrete from those of their original, so I’m not sure aliases in outlines is a good way to indicate links and I don’t think this scale well past a few 10s of items.
Also, how does your method differentiate linked notes from actual children? If you want more of an overlay listing, you could experiment with Hover Expressions, using action code to set a list of linked items.
I think what would suit would be to be able to use Roadmap view in a way not currently possible. That is to have a torn-off Roadmap re-focus itself to display the currently selected note’s links. For now that’s an idea and a feature request for someone to make.