Just wanted to say great job with this post! I like that you were quick to respond to questions/criticisms, updated the body with edits, and the huge thing of also updating the title and prominently calling out the right answer and the user that provided it.
While your question is answered I’m still left wondering if part of your question was if you can have a circular face cam in OBS. You can have a cam layer be masked by any shape, so yeah, no problem.