If you make an assertion, you should be prepared to defend it.
Plex cannot passthrough DTS-MA or True-HD; it can only extract the DTS or AC3 Dolby Digital cores. Handbrake, likewise, can only packaged the extracted AC3 into an M4V container because M4V cannot contain True-HD or DTS-MA audio. It can also transcode DTS to AC3 for an M4V container, or package DTS into an MKV container.
Hey, this is not a debate. This is an exchange of information.
I don't have to document everything.
If it's important enough to you (like it was for me), you'll dig deeper yourself.