I am not quite sure what you mean with "GIF previews". The preview for frame-animations is in PEBI since 0.18 but can also load GIFs since our latest update 0.19 (with mixed results I am afraid :/ ).
If this doesn't answers your question you can join Vanlaus Discord https://discord.gg/udchehMgxt for easier communication, if you want.
(Sure I will answer you here too, but getting notifications about new comments is not really a thing ^^" and is more clunky than a direct chat)