so far this combination worked when using myfaces-core.
extval-38 (as well as the wiki) shows the required dependencies.
the mentioned issue describes that there is an issue with mojarra.
the good news: the issue is fixed and you can use this combination.
i hope a lot of you (who signaled interest in this combination) will start to test the new version or a patched version of v1.2.2 you can find here.
some details about the original issue:
the generic support module is required, if a component lib does special things behind the scenes.
e.g.: casting renderers,...
so the module uses cglib to allow that. via an extval startup listener the module installs itself. the issue with mojarra is that it uses early configuration. so the extval startup listener of the module gets invoked too late and important configuration tasks are performed by an extval-core class instead of the lazily installed class of the generic support module.