This question is mainly directed to Puybaret.

The Plug-in developer's guide states:

If you want your plug-in to be able to run with Sweet Home 3D installers available on this web site, take care to keep it compliant with Java 5

I think this requirement was valid for a very old release, since the latest installer comes with Java 11, however I could be missing something not so obvious.

So, the question is:
which Java compliance level could we safely use for new plugins?