Hey @John,
Thanks for reaching out! Unfortunately the changes you’re describing are, indeed, possible, but would require code customization. We don’t offer support for writing custom code, but in general you should be able to get started by heading into your plugin files for The Events Calendar and navigating to src/Tribe/Tickets there – you’ll across the various files in this folder how the tickets system works and how attendees information is generated, whereby you could add custom code to add your custom data to the Attendees info.
We also do have a plugin in active development to make this all a lot easier, and automatic. It’s still a ways off from public release, but just wanted to share that we are working on a way to improve this because, currently, it is far too difficult to add custom info like this.
Cheers!
George