I really like to use Add Tag/Parent/Icon ‘Search for an element’ pop-up. IMHO, this is an example of clever and thoughtful programming, bravo! Hope you will add more commands here and transform it to something like ‘Command Palette’ (especially on the desktop app).
I think someday this pop-up may become some kind of a SN ‘control center’: so pressing ‘/’ anywhere will bring you all the available commands in current context (create new card, join card, share, create an external link to a card, move selected card to Junk, enter Filter panel, go to global search etc). Fuzzy search is highly welcome! 
The only thing, that really bother me is that ‘Search for an element’ pop-up is closed after each edit (when you click on an item or press Enter on a ‘Finish editing’ menu). So, when you want to add Tag, Parent and a Colour you are forced to open ‘Search for an element’ pop-up three times - this is annoying.
So, here goes the main suggestion! 
- Pressing Enter (or clicking) on a ‘Finish editing’ menu or an item in the list, which does not supports multiple selection, should close the pop-up (as it currently does). Pressing Cmd+Enter (Cmd+Click) should finish the current editing and return to the main ‘Search for an element’ field. That’s it!
Example:
-
press ‘/’ to open the pop-up
-
type ‘Tag’+Enter, ‘Tagname’+Enter, ‘AnoterTagName’+Enter (to select two tags) and now press Cmd-Enter (or Cmd-Click) on a ‘Finish editing’ menu: you are now back in the ‘Search for an element’ field.
-
Type ‘Parent+Enter’, ‘Something’ to select ‘Something’ as a parent and press Cmd+Enter (Cmd+Click) to return to the ‘Search for an element’ field.
-
Type ‘Color’+Enter and ‘Yellow’ to select color and now press just Enter (Click the ‘Yellow’ menu item) to confirm the color and exit the ‘Search for an element’ pop-up. You have added Tags, Parent and Color to your card without closing and reopening it three times.
What do you think? Is something like this possible?
- This is a smaller one: allow multiple Parents selection (as with Tags).
