[gb160]

So, the long awaited 'h264 interlacing fix' from amazon has finally arrived, and its not good news on the Kodi front guys.
Using a TVHeadend server, and the TVHE PVR client, I get beautiful deinterlaced playback for about 5-10 seconds, then the players locks up until a reboot.

The positive news is using the 'dream Player TV' app, which is just a TVHeadend client...1080 interlaced h264 content is playing perfectly now on the fire stick 4K, it definitely wasn't before as I checked when I first got the device.

Im using the 18.2 RC, Im happy to provide logs etc if they can be of use to anyone.

I am looking to update to Kodi / firestick also. Currently, I have a FireStick 4K with PlexKodiConnect, playing a video with acceleration works fine. In contrast, IPTV in FHD quality only works for a few seconds and Kodi blocks.
When I disable hardware acceleration, videos from PlexKodiConnect do not work smoothly, IPTV starts to work.
Now every time I turn on or off hardware acceleration depending on what I'm watching. 

If you want to watch x264 interlaced content then look for another device, its still borked on the firestick 4k, and Amazon dont seem in the slightest bit bothered.