I have a client the undertakes market research. We were aiming to use Membership 2 Pro for her users to sign up and adding details such as:
When she has a relevant project we were hoping she could search the members based on those criteria and email the resulting members.
I have found this ticket: https://wpmudev.com/forums/topic/membership-2-pro-customise-membership-pro-support
but it seems to be directed at BuddyPress rather than WP.