I tried to link to an existing note by using the [[ call it finds and links to a note if you know the title of the note, but cannot do an inline search by some text from within all notes. This would massively improve the workflow of linking to existing notes in my view.
We don’t have exactly this feature, but we have completely new search coming in Agenda 19. It works completely differently to what it is now, and it should be useful for finding note titles without losing your place in the editor. Results appear in a popover, instead of taking over the whole note list. I think this should be a good solution for you.