WordPress Membership Plugin
Your post above says The form builder will include all the custom fields value in the admin notification email by default. So you (the site admin) can see what values a member filled in for the custom fields. It doesn’t do any email tags.
This is not working on my admin notification email. I tried using the {raw_custom_fields} tag in the email per one of the plugin’s help article but that didn’t work properly.
If the registration form fields can not be included in the admin email notification then please let me know how to request a refund. Thank you.