Acymailing plugin - Not add multiple group members as Joomla user

Right now if you use the Acymailing plugin.
And enable in the plugin to the add group members in Acymailing.
And sell tickets trough the group registration
Also you use the option to login the joomla user before buying
And the person is buying tickets with other email addresses then his (joomla) email address.


In this case when people indeed buy more tickets it is possible that 6 email addresses from friends can be associated as that particular joomla user. 
Personally I only see downsides and only expects that the main invoice email address is that user and not the members. 

I suggest a setting:
Add group members how?
1. Add all group members to Joomla user account
2. Add only the first member
3. Add only the payment information email as joomla user
4. Do not add as joomla user

Why it is not right for me?
I use an academy and people gain certain rights. 
I send out email to people with certain rights. 
Now when I filter on a Joomla user with that rights I get all 6 addresses for that one joomla user in Acymailing. 
So all the group members get the email that they have the right, though they do not have that

And I believe it will give a lot of trouble in Acymailing to have multiple addresses connected to one joomla user account. 
With automation, editing the email addresses (for joomla user you need to be logged in) and I can't imagine how that works us expected