can a httpd fcgi module start sending generated response while the request message body is still being transmitted to the app?

Hi all!

I was trying to send a (chunked-encoding) answer that was being
generated after each chunk of the POST-ed message body was being
received. I tried with both mod_fcgid and mod_proxy_fcgi and
both seem to buffer output until all POSTed message body was
delivered to the application
(they just passed back what was generated after the headers were
accepted, but not after the body started coming. In fact, mod_fcgid
kept crashing if much of the response was building up)

So is this the typical way httpd's fcgi modules handle communication
with a fcgi content generator? won't alternate write/read over
the STDOUT_FILENO that connect the server with the app? (i.e. treat
it as a bidirectinal pipe or open another unidirectional pair?)
If so, have you heard of any better httpd module that can solve this?

any answer/idea or pointer will be greatly appreciated!

best regards

Tand Read