Structured Data plugin
This places structured data within a given wiki page that is aggregated to a central sqlite db. Both this and the struct plugin are maintained by the lead maintainer of DokuWiki itself, so they should stay up to date in the foreseeable future. Either one would allow more sophisticated use of the RefNotes plugin. The sqlite plugin is required for it to work. Another alternative is the strata plugin.
The present editor has not yet tried it. It seems like it may be more quick for an editor to use, especially of the data block can be set up in a page template. However, the data isn't validated as with Struct, so there could be downstream issues resulting from that.