This could also work as a quick fix for a bug sometimes happens, when it does not assume the new thumbnail during the live, and you end up with the thumbnail of the previous livestream you did (spoke on Discord to a member of DLive Team who confirmed this also happened to him actually.) I would say this is a really important feature.

They used to have it I think, not sure why it was removed.. also need to include vod naming also.

This idea has come up a few times. I'd like to be able to save around 12 or so Streaming Templates complete with auto-filled title, language, category, and thumbnail (options available on dashboard). The streamer chooses a template from a dropdown, makes desired changes, saves and starts streaming. Would save time & no re-uploading commonly used thumbnails. It's particularly challenging for IRL streamers who use a phone & streamlabs app and don't have all digital assets available on the go.