I'm not sure why LADSPA is in the title. Cabbage exports plugins as native Linux VSTs (and LV2s if you're using Cabbage v1.n). Make sure you add the location of your plugin folder to your VST path. When i run
echo $VST_PATH from the command line I get the following:
~/.vst is a default location for most audio software, so if you simply create that folder and place your plugins there it should work fine. For what's it's worth, I've been running most of your examples on Linux without any issues.