Hi Jim,
From conceptual viewpoint, mod_unimrcp is just an alternate implementation of an abstract ASR/TTS interface FreeSWITCH provides.
Therefore you can use it exactly the same way as other ASR/TTS modules.
See scripts/javascript/ps_pizza.js in FS tree for a working example.
The only thing you should know and change there is module name
< var asr = new SpeechDetect(session, "pocketsphinx");
> var asr = new SpeechDetect(session, "unimrcp");
Typically you can specify any grammar your MRCP server supports.