I also was sure there was already a post in the Ideas category but I can't find it so I've taken the liberty of moving yours!
This is something we've thought about quite a bit but don't have a concrete direction on yet. More broadly, we'd like to have a single way to express "map this existing data from my form context on this geo question". This would also address the need expressed in Mapping within a repeat group : show already drawn objects on the geowidget map
Thanks for describing your use case and getting the conversation started!