The latest API uses access group permissions for windows that appear in access groups. Therefore for APVc to be accessible I think you need to create a window definition for it and add it the users acesss group.
I would like to know what BackgroundHALShouldPause does, and how to use it. While it's listed in the HAL Primitives report, it is not used in source code and it doesn't appear in the LMS HAL...