Happily, after a chat with @alanj he introduced me to the Frontend Admin plugin. I’ve been really impress with how easy it is to setup, design a form to edit user profiles (including Custom Fields) and use. V cool.
(Aware I’m talking to myself , but hopefully providing helpful into to others in the future)
Out of interest, I tried dropping the form shortcode into a Bricks page and although it showed in the edit page, nothing appeared when I looked via the front end.