Hi all,
because Hyperion does not support the internal Framegrabber from Kodi Matrix,
i needed a capture card and got some Mirabox HSV321.
Unfortunately I had to realize it has no CEC passthrough!
After removing the encloser and getting a closer look on the board,
i noticed that the CEC pin from the HDMI-in is connected to one of the ic (maybe there is at least a working CEC input, did not tried it) but the CEC pin from the HDMI-out is unconnected.
I decided to isolate the CEC input from the rest of the board by desoldering D3 and wanted to test
if maybe a direct connection from CEC in to out does the passthrough job?
Yes it does 
I added some pictures to show were you need to solder the bridge.