The new images look fantastic, Chad. Really like them.

Would it perhaps be simpler if instead of developing a "Change columns" UI, actions can be added to move columns, something more along the lines of what I mocked up for T9280, i.e. a simple action with two parameters, rather than a monster action with parameters for all existing boards?:

I mocked up an alternative UI for this for T9280 (not having found this task, or the others mentioned there).

I'll work on updating the patch to improve the visual feedback and then arc diff it. Thanks for your willingness to consider it.

Here is my patch. I can arc diff this if needed (though it will take me a little while, since, as you can probably see, I checked out Phabricator using hg-git rather than git itself, so I will have to do some trickery to use arc diff or clone again). It does not include the changes from running ./bin/celerity map.