FVWM: Is there a way to stop a window from de-iconifying itself?

I use GNU Emacs (and fvwm3), and unfortunately a small irritation with
this is that GNU Emacs has a quite irritating habit of de-iconifying
(and I think raising itself to the top of the window stack) any time it
finishes a long-running Lisp operation. If I start an operation that
takes a long time and iconify GNU Emacs, I want it to stay that way,
I don't want it to suddenly spring open like a giant modal popup.

This behavior appears to be burried deeply inside GNU Emacs so that I
can't modify it with the normal GNU Emacs ELisp tools. As a result, I'd
like to have fvwm just ignore any request from GNU Emacs to de-iconify
itself. Is this possible? There is the 'IgnoreRestack' style option,
but in experimentation this doesn't seem to stop GNU Emacs from
de-iconifying itself, although it may stop the raising if GNU Emacs is
already de-iconified.

Is this an EWMH hint, so that I want EWMHIgnoreStateHints? I'm wary
of ignoring all EWMH (state) hints due to potential side effects.

Thanks in advance for any advice.

	- cks