AFAIK Geany is not mainly distributed via some sort of repository like "brew" or so but via downloadable installers from our website and so I thought the update checker plugin would do the same job on Macos as on Windows.
I thought I had seen @techee make bugfix builds on the geany-osx repository, I guess if they get uploaded to the Geany website that would be ok, but then whats their version, if its the same then the update checker won't notice?