(I'm taking Jaap's answer at face value. I don't remember much about mod_perl.)

What are you trying to accomplish? There might be other ways of accomplishing what you want to accomplish. One thing you could do is to have a barebones handler that loads up the full module and calls it:

sub handler {
   require Full::Module;
   goto(&Full::Module::handler);
}
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(You might have to fool with the args in @_ a little. I don't remember what args a handler receives.)

Of course, once the module is loaded, it will stay loaded.