hi @ActionA!
So i tested it, and actually if i enable the acceleration for the omxplayer the video is not freezing anymore, BUT for mkv files there is no sound anymore.
Here is the kodi.log file, you can found the other log above: http://dsh.re/ce9b8
It is almost like the same that @DerDaumen mentioned here. So it is like somewhere it is working only with this acceleration, but on the other hand it is disabling the sound for mkvs: Video playback halt at startup (Aug 5 update) - #3 by ActionA