How can I shrink ECB's compile window when it loses focus to an edit window

[John Yates]

I use ECB (2.5-dev) with a persistent compile window. I have it customized
to grow the compile window at various times. That works nicely.

One remaining frustration is when the compile window has focus and loses it
to an edit window (as opposed to one of ECB's special windows or the
minibuffer). In that case sometimes the compile window shrinks (yeah!) and
other times it does not (boo!).

Is there something I can do to get more consistent shrinking? A felicitous
hook variable perhaps?

(For what it is worth I am using the emacs tip, i.e. 25.0.50.1 and the
2.5-dev branch at github.com/ecb-home/ecb.)