[noggin]

Well, this is sooo great. They advertise HDMI 2.0 and now I just can use the half of the product. Sad.

Are there any SoC HDMI 2.0 boards around without a hardware bug like no DTS HD?

The S905 series AMLogic (and I think S905X) both support HDMI 2.0 2160/50p and 59.95/60p output with DTS HD and Dolby True HD in LibreElec (and in some cases Android) I believe. The ODroid C2 is a good example, as is the Wetek Hub. Beware the X variant only has 10/100 Ethernet support. The non-X variant has GigE - but may have slightly reduced codec support (and no HDR?)

Edit: So it's possible to passthrough HD Audio via DVI <> HDMI? Which adapter do I need ... I though DVI is mostly without sound.

"Pure" DVI-D has no audio and is often 0-255 RGB only - it is effectively a sub-set of HDMI. However it is possible to carry all but the CEC elements of HDMI over a DVI connector. And this is now quite widespread.

However HDMI and DVI are electrically and effectively "protocol-y" identical (apart from HDMI having CEC) - with the audio in HDMI being carried in the gaps between video information on the same pins as the video signal (i.e. audio isn't on separate pins).

Many video cards with DVI physical outputs have DVI to HDMI adaptors that enable audio outputs when present. AIUI many (all?) Apollo Lake cards with DVI output are actually using an HDMI 1.4 to DVI output solution (basically bringing the HDMI on-chip output to DVI connectors not HDMI) and don't even need bespoke adaptors to enable audio ? This is why some Apollo Lake devices have two HDMI outputs (the on-board HDMI 1.4 and a DP->HDMI 2.0 offboard conversion)