With Clip Effects you can insert any VST2/VST3 plugin that you can insert anywhere else in the montage or the global master section. There are only a few exceptions of plugins that can’t be inserted as Clip FX such as Resampler and External Gear.
Otherwise all other built in and 3rd party plugins are generally available as Clip FX. It’s part of the beauty of Wavelab and the montage workflow.