I just noticed that the plugin af_redditimgur might need an update if you have time because of gfycat changes, I suspect.
I’ve looked at the code in the plugin and as far as I can tell the plugin should embed the MP4 version, but it’s actually the -size_restricted.gif that is in the img tag once the feed is loaded.
as an example a reddit post with link to https://gfycat.com/OrneryAmpleArrowworm will be embedded as https://thumbs.gfycat.com/OrneryAmpleArrowworm-size_restricted.gif but should embed as https://giant.gfycat.com/OrneryAmpleArrowworm.mp4
Running on commit 5a35b31
Debian 9.5 VPS