Can I re-bump this thread to ask if any #gsoc-2021 developers would like take this up? In summary the request is for ctrl/cmd-clicking multiple tags, to do an 'AND' search for notes with those tags.
It was brought within reach by the efforts @naviji in a GSOC2020 search engine project but sadly not quite implemented as a ctrl-click feature, only by typing the query manually.
This feature alone would be a massive functionality boost, but if a GSOC project needs more content, a great stretch goal would be to implement a tree structure to store tags, with a drag-and-drop filing method to arrange them. Anyone interested?