Full passthrough (TrueHD/DTS-HD) is a standard CE feature on just about every CE supported device.
Homatics Box R Plus / Dune HD R Plus / Rocktek G2 / Nokia 8010 (s905x4-k)
Kinhank G1 (s905x4-j)
Amazon FireTV Cube 2nd gen (s922z)
All these devices have DRM support for the Android/FireOS side.
The R Plus from Dune & Homatics, Rockteck G2, Nokia 8010 are all clones, and using slight variations of the same AndroidTV firmware. The Dune HD has the benefit of including an IR receiver and SDcard slot. **The G2 includes IR receiver & sdcard slot. Not sure about Nokia, the Homatics R Plus has no IR or sdcard.
All of these boxes are from SEI, so the Homatics box has the best company support, because Homatics is SEI’s direct to consumer brand.