I’ve been using fulltextsearch_opensearch for a while even though it was abandoned, manually bumping the version number. It finally stopped working, so I forked the project and have a version working for myself on two installs. I plan on releasing it, but would like a few more people to test it first.
To be up front, this was done with a lot of help from Codex, taking the current state of fulltextsearch_elasticsarch and re-applying the fork to OpenSearch on top. I have not updated credits or much else as my goal was to just let people stuck on old Nextcloud update. cleanup will be the next step.
Any problems please do open an issue on the project !