Correct. Biggest lacking feature.
While this maybe a bit out of topic, but just out of curiosity why do you think that adaptive spawning is any good (trying to run more processes in given time period than started) - "stepping" back to how apache operates with its prefork mechanism (iirc there are even people from php-dev community which suggested running apache with start/maxservers identical so there is always constant number of childs (for php processing) to avoid unwanted/unexpected resource consumption?
There should be reasons why it was also dropped from the other external process manager lighty/spawn-fcgi and never planned in webservers like nginx ..
I would rather want to see one day php (master process) return FCGI_OVERLOADED for the webserver/application to decide what to do next.
rr