Hi rblezer
I got your point, let me explain a bit here.
When we implement this K2 Data migration component, Joomla have not supported custom field (as its now) yet. Hence, there is no place to store the K2 extra fields and we import them to JA Content Type plugins.
To show imported K2 extra fields, you will have to customize template to integrate with JA Content Type plugin.
I've also forwarded to our development team for further review on this so it can support to import k2 extra fields to Joomla custom fields.
Regards