As noted elsewhere in this thread, the beta build with tsMuxer works very well. I'm having no problems with it remuxing on the fly for files that have suitable h.264 video streams, and both the AC3 passthru and DTS passthru seem to work well. The only issue I'm seeing, as others, is the files stop streaming correctly about 7-8 seconds before the end of the file.
Happy to provide logs if it will help. Thanks!