Hi
First of all, I would like to apologize for my rude tone. I was very frustrated as I needed this feature quite badly. I verified the problem further and found out that the maintainer of the Geany plugins package ( I use Manjaro) did not add this plugin anymore. Or something went wrong during the installation. When I built the plugin myself from the git sources , I could select it again. So I contacted the maintainer directly and asked him what was going on. Sorry again and thanks for your work.
Sincerely JG