Quick Open is very good improvement! Thank you
I would suggest:
When opening Quick Open window, it could already show last opened notes as a list (not only notes opened in Quick Open but all last opened notes (Notion or Craft have similar functionality). When you start to write your search, it would of course disappear/be replaced by search results. The usecase is obvious: We will use Quick open to - well - quickly open. And I would say that more than 50% of files you need to open is between your last 10 or so. Of course, sorting by last updated in sidebar is very similar - but 1) some users may use other sorting or filtering already and 2) quick open is quicker.
When searching for notes/tags, it could sort the results again by last opened (if notes have such property, I am not sure. If not, it could be at least sorted by recently modified). Usecase: When I open some file or tag using Quick Open, chances are high that I will be soon opening the same file or tag (rather than file with similar character combination which I type into search bar). So if this file would appear first (and other recently opened files which suits my search would be sorted below), it would be best solution IMO.
My suggestion is that I would appreciate having listed all results irrespective of whether they are files or tags: E.g. writing “Classic” I would like to see all notes and tags containing this word. Of course, tag-specific search is super (by prepending #), I would not choose it. Yet in default, I would also list tags - files and tags together, again both best sorted by last open.