We could use a icon based typeahead (instead of icon-selector) in some situations where we want more than 16.
My only (mild) concern with this is that object types may become slightly ambiguous in some contexts: currently, icons are (at least mostly) unique across object types. A tag icon or a briefcase icon is always a project. A calendar icon or a cocktail glass is always an event.
I'm not sure this is ever actually confusing or ambiguous -- and if it is, we'd be better off tackling that ambiguity rather than relying on users to memorize different sets of 16 icons to distinguish object types.
And this claim isn't even true because "Calendar" is already an event icon and a project icon (???).
Maybe nice for the UIs to let you select defaults/favorites, though? e.g., keep ~4 defaults (briefcase, tag, lock, users for projects), add a few of the icons you used most recently for that object type, and then let you typeahead anything else.
(I renamed the "Up for Grabs" column to "Ready", and kicked this out since it doesn't have detailed technical instructions that a new contributor could follow like the other tasks in that column do.)