Hopefully this isn't already obvious, but you can configure your multiboxing software to only enable CTM while you're pressing the IWT button. This would let you broadcast mouse right-clicks without worrying about run-offs.
Example:
* IWT button -> on PRESS:
** Enable CTM on slaves
** Send IWT key to everyone
* IWT button -> on RELEASE:
** Disable CTM on everyone
I'm pretty sure all of the competent software can do this, including HKN, ISBoxer, etc.
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