I think that you might misunderstand the problem that the majority of people here are complaining about. Please take another look. Your post should not be labeled "Best answer" since it does not address the actual problem. In particular it is not simply about a preference for the old email behavior, but rather thatthe new behavior is defective. The is a bug, not a matter of getting used to an intended change.
The problem: I can receive invitations on my alternate email addresses, but I cannot do anything with said invitations.
Clearly it should not be possible to get invitations that one cannot accept.
The defect stems from the fact that when I log in with an alternate email address, the system logs me in as if I logged in with my main address. So far so good... But when I receive an invitation, that invitation is associated with my alternate email address, and is therefore not accessible at all no matter how I log in. There is simply no way to get at the invitation to accept it. Clearly not a matter of preference, but rather a bug, since it does not make sense to receive an invitation that one can't accept.
Please take another look at this thread. The problem has not been addressed nor acknowledged.