Hi arouillard44 ,
I have got information from experts that you will be able to use fields from profile extension for linking after the product release in February 2018, if there are no furthe delays.
At the moment, I would suggest not to link your event with configuration if email is not the unique field to work with.
instead fire an API call to profilesAndServiceExt and then get all relevant profile details.
Use this data to then fire an API call to event and pass everything needed for personalization into CTX.
Sorry, its not elegant but given the circumstances, it appears to be the best solution.
Regards,
Vipul