I'm glad the add-in is working well for you (both Bucky and Cristophe).
Creating a profile is a pretty tricky process. Petr (Serviio's creator) has an introduction here:
It involves editing the profiles.xml file, which you can do from the Advanced tab in the plug-in ("Edit Serviio Profiles File" button on the right). The LG MS400H looks not to be available in North American and I can't even find an official set of specifications
for it. I did find this page:
But that just scratches the surface of what containers and codecs are supported. If you have a more detailed set of specifications, it'll help.
Regardless, your best bet is to ask for some help in the Serviio Transcoding forum (http://forum.serviio.org/ and click Transcoding). There is an active community there that should be able to assist you in getting your device working to it's fullest potential.