clicking the"edit jwm Settings" launcher does open a set of files in geany, as expected, but
while that geany window is open, the controlCenter window becomes unresponsive.

unresponsive, as in:
If you drag that geany window (or use WinGrid keycombo to move/resize it), you will notice that the controlCenter window isn't even being repainted; a rectangular portion of (or all of) the controlCenter content is now blank. Also, clicking X on its titlebar to close it has no effect. Well... no effect until you close the geany window ~~ if you've tried to Xclose the cc window while the geany window was open, cc window immediately closes following closure of the geany window (like, the earlier titlebar X click had been recognized, but not immediately acted upon).

This can be fixed by adding a tail-end ampersand character into this"action" line (line65) within /usr/local/bin/antixcc.sh Whoops, now that I'm looking, found another identically bugged launcher needing a tailend ampersand added:
line503

Thanks skidoo - bugfix deb on its way