The Propachi plugin has served well for rapid testing of changes to
citeproc-js, and more recently as a workaround to support capitalization of sentence-case subtitles in styles that require it (APA being the leading culprit there).
Bug reports against the processor are now very infrequent. Since the release of the latest APA style revision,
citeproc-js has been extended with a runtime toggle to enable sentence-case subtitle capitalization, and Zotero has moved to set the toggle automatically when the APA style is selected. It is a rare case indeed when guiding a user through the installation and use of the plugin is worth the effort.
Processor development is still somewhat active around multilingual functionality, but as this is used exclusively by Jurism, where I control the release cycle, there isn’t a need for Propachi releases that extend or improve that layer of the processor’s capabilities.
I’m inclined to remove the plugin from the Jurism site to reduce clutter. If anyone feels that it should continue to be updated at each point release, please let me know. I’ll be happy to hand over the keys with instructions on its (simple but hackish) build and release process.