Hi @webdevmelb – super long getting back to you but here is an option for assigning a membership level as part of event registration:
This recipe will assign a default level to all WordPress New User registrations: https://gist.github.com/strangerstudios/dd994551e2cdcc6ec5a3
This recipe assigns the default role to ALL user registrations, so you do need to adjust it. First, I would suggest removing lines 7 and 8, since this will unhook PMPro’s ability to control how users register.
Then, if you don’t want every WP User to have this level, you will have to adjust the code further. If the user created as part of event registration has any specific capability or role that you can check, you could add that as a conditional check. Or, you can ask the events plugin if there is another hook you can use specific to their user registration that you can use instead of the core WordPress hook user_register
.