Does the auto populate function work for any field with the same name as the field name in the account?
=> No, it doesn't. You would have to use this plugin
eventbookingdoc.joomservices.com/synchro...#joomla-user-profile
and map the field in user account with related field in Events Booking for auto-population
However I'm not sure how the fee field works. Can you give some examples of usage of a custom fee field?
=> You will need to read documentation at
eventbookingdoc.joomservices.com/basic-s...ds/custom-fee-fields
to understand how it works, then try to setup it. If you have question duration setup (You need to tell me how you want it to work). I will try to think about it and give you the answer
Regards,
Tuan