How do I edit Minuum's custom dictionary? I've noticed that every time you tap on a "new" word, Minuum adds it to its custom dictionary verbatim, i.e. if it happened to have a capital letter, it will gets saved with the capital letter.

How can I edit its dictionary?

I'd like to both edit some words, such as these incorrectly capitalised, and add new ones, such as aa'bbbb that unless I add them manually won't be automatically saved.

Yes there is an "import android dictionary" feature, but while this may work for adding new ones, it will most definitely won't work for editing existing ones.
http://support.minuum.com/forums/210127-minuum-support/suggestions/4099381-options-to-view-edit-remove-dictionary:


  We've now added support for backing up (importing/exporting) your data
  by going to Minuum settings and choosing "Backup your data", which
  will save a file to your Downloads folder.
  
  You can still remove words from the dictionary by long-pressing on
  them when they appear in the word suggestions bar at the top of the
  keyboard.
  
  We're still working on making it easy for you to directly edit your
  dictionary on your device.


– The Minuum Team (Admin, Whirlscape) commented  ·  August 15, 2013 20:59

So, since I can both delete words and add new ones, and as long as this feature is not properly implemented, I'd say that's it.