I know one can use advanced searches for finding documents that are tagged with all of a set of tags (eg: recipe AND dessert), rather than any of the tags selected, but I find it tedious to go through that method just to find the intersection of all tagged documents with “dessert” AND “receipe” or any other set of tags.
Is there a feature, current or planned, to allow me to click on multiple tags in the list of tags in my database, perhaps with a modifier key or a contextual menu, so that I get the boolean AND result rather than the OR result?
Yes, switch to the Tags view (View menu>As Tags, or CMD-6) and shift- or CMD-click from the list of tags in the right column to view the intersection of the selected tags.
Finding the union of tags (OR) can be accomplished by switching to the Three Panes view (View menu>as Three Panes, or CMD-5) and shift- or CMD-click from the list of tags in the Tags group.