I have a method of doing this that honestly I would prefer even if I could afford the SurCode encoder:
1. Export video with the H.264 Blu-ray preset, and export audio with the Waveform preset (make sure output is set to 5.1). This will leave you with one .m4v file and one .wav file.
2. Use eac3to to extract 6 mono .wav files from the single .wav you created in step 1.
3. Use DTS-MA Encoder Suite (easy enough to find for free) to encode to DTS-MA 5.1. This will give you a .dtshd file.
4. Remux your .m4v video file with your .dtshd audio file with tsmuxer.
Done.