Can a member use a different email address on their GoCardless instruction?

When a user is logged into their sheepApp account and chooses to renew, then chooses to renew by DD, the GoCardless integration with data from the account is populated to the mandate. If the user amends that data and submits that data then that record syncs to your sheepCRM contact record for them and pushes the email in as it is a key matching field.