Hello,
Today I figured out the source: see my answer to that question.
It's still not clear how this BLANK buffer was getting created on startup, since I have no idea how hycontrol-window-display-buffer was getting called, but I'd like to suggest that the name of that blank buffer be changed to something that makes its source and purpose more obvious. Perhaps
(defvar hycontrol--blank-buffer (get-buffer-create " *hycontrol--blank-buffer*")
? Any user who does hycontrol-windows-grid and triggers that will see the extra buffers with that name, and if such buffers just show up in the buffer list, it'll be obvious that they can safely be killed.
I don't have any strong feelings about the name, just something more helpful and meaningful -- and searchable! -- than "BLANK".
Regards,
Dan
-- Ceci n'est pas une .signature.