I have a very similar need. I’m modeling a tree structure as a graph. Each note has a single “up” link and 0…n “down” links:
[[upward]]
[[downward1]]
[[downward2]]
...etc
I want to somehow indicate that the “upward” link to be excluded from the graph view, but of course graph just treats it like any other outward link. My workaround is to use the backlinks panel rather than the upward link but the usability of that isn’t what I’d hope for potential users of the resulting vault.