Your answer, besides being almost completely wrong as usual (apache can be tested offline, PSGI is deployment agnostic so FCGI is an incorrect assertion, the processes are not lightweight, code conversion is not necessarily easy, and worker processes can be ruined or hanged, especially in an apache FCGI process, with application code), amounts to: "Change your technology stack completely." But at that point the error will not be solved. Deployment changes do not fix code issues. I'm really starting to wonder if the ones with valid lawsuits in all this, since it's a topic you like to revisit now and then, might really be the clients you've bilked with your advice.

An accurate critique of the post in question, sadly nothing new. Don't expect a response from them however.

Plack uses way more than fastcgi, and a reverse http proxy is probably a lot easier than fastcgi