This came up while we were discussing the Gwenview release notes for Applications 18.04. It would be nice if Discover had a command-line flag to temporarily prefer local AppStream data from /usr/share/metainfo. This would be very useful for locally testing AppStream changes so you could see how they would show up in Discover.
There is no command-line flag (yet), but you can achieve that behavior by setting `PreferLocalMetainfoData=true` in `/etc/appstream.conf`.
That'll do, thanks!