Same Email Address Setting and Email Deduplication Rule shouldn't be allowed to be used together

When configuring an event online registration, the setting called 'Same email address?' and deduplication rules that include email in the criteria shouldn't be allowed to be saved together.

The result of this configuration is that when a participant registers multiple participants, and enters the same email for more than one, the system will deduplicate those registrations and tie them to one contact instead. This scenario gets worse when participant no. 1 is the contact those registrations are being tied to and there's a payment involved. The resulting contribution record somehow turns into multiple transactions to batch instead of one. Things get even more innacurate if this contribution has to be refunded or cancelled.