I think I have noticed that if a note showed in hyperbolic view has many related notes, the view does not indicate that there may be other notes out of view. Moving around in the view by dragging will show that there are more notes. Would it be possible to select how many notes that is shown at the same time?
Not at present. The current design gates the view at max 5 links traversals from the focus note. Your question does raise the possibility of having link stubs—like, not same as—those in map view, i.e. indicating more-but-not-drawn content.
A chick-and-egg here is that one could link for Hyperbolic view efficiency. If X and Y should be ‘linked’ in the general sense for Hyperbolic review, then one could add such a link, rather than just look at links made for other purposes for an accidental relationship.
A different approach to seeing more might be to use neighborsWithin(scope, distanceNum[, linkTypeStr]).