MatrixTV is using Gotham. Deinterlacing there works I think. But In Helix there was no deinterlacing for imx6 platform for a month back when fritsch starts working on cubox-i support . Current state is that for SDTV works but not (yet) for HDTV. How long it will take to get there no one knows.
That's why you can't mix all systems as they are the same. Even if running same XBMC/Kodi version.
Yes, support for tbs matrix and udoo will come officially to openelec. Probably after 5.0. I'm working on this 2 platforms.
You have to understand that for Raspberry Pi there was lot of work done to get all this performance out. For imx6 someone still needs to make all those things. And the progress is very good (from 0 to SDTV in a month). And it is not just matrix issue - it's imx6 issue.