I hope they upstream their implementation of Web Extensions to WebKit.
I'm not interested in using a proprietary browser, and hope for a release under a free license at some point. But a free WebKit-based browser with Web Extensions could have interesting properties regarding battery life on mobile GNU workstations.
If there's one thing they should release as free software it's this. I'd be disappointed if Orion never becomes free software, but it would hurt a little less if GNOMEs epiphany could benefit from the extension support
I don’t think WebKit would be particularly interested in this.