Ok, so this is for last night, I wasn't able to connect to write...
So I finalized my ideas / proposal for a feature for SRM to be able to import library functions into the running script's function table. It turned out that the import function was the best method to use. Much thanks to Derick again, for answering all of my questions about the inner workings of SRM and PHP. So, I started working on adding this to the SRM extension. Basically, this is all there is to it from the PHP side:
$srm = new SRM('/tmp/srm.socket');
$srm->import_library(); // import functions // OR $srm->import_library(true); // import functions, and overwrite functions that may already exist
And that's pretty much all there is to it. I've got the code to handle the method call now, and I just have to clone and slightly modify the SRM class's method handler.