I'm trying to create a plugin that will store some metadata to different layers of my image, then process said metadata after exporting the image to the ORA format. From what I've seen, different kinds of metadata are stored when exporting a PNG file (which is what ORA uses internally), and the most appropriate one seems to be XMP, given that it's basically a key-value map, so being able to either set fields on the existing XMP map or set the full XMP map for a layer at once from the scripting context will be very useful.
Yes, this is something we want ourselves too, but it'll take some design work on how we're gonna get our exporter to take metadata and use it.
Well, as I said, the exporting part seems to be solved. The PNG exporter is already taking into account metadata in a few formats. What's missing right now it's a way of changing said layer metadata through scripting, unless I didn't understand your point, in which case I apologize :).
Setting to unassigned, since these are wishes that I don't have time to work on.