Is it possible to have invoices / statements auto-sent to a certain e-mail address if I have a Personal/Team PRO subscription?
Custom invoice email addresses are only supported in the Organization plans (https://www.bitrise.io/pricing - Billing email management).
On Personal/Team subscriptions the invoices are always sent to the owner account’s email.
If you activated it for your account then of course you can change your account’s email to the one you want to send invoices to, but you can’t set a separate email address for those (separate invoice email address is an Organization plan only feature).