If I understand correctly, there are certain limitations to using external user accounts (the self-registration service too), when it comes to tracking users' progress and performance across the LMS.
As we are working with elderly test subjects who might not be very technologically inclined, we would prefer to make signing up and in as easy as possible, and so the Adobe ID is simply not ideal.
Is there any alternative?
With External user Adobe ID is not required. You just need to send the external user registration link to the user where he will be asked to register himself. User can use any email ID (his personal email ID) to register himself to this external group and you will see the increased seat count at your end.
Once registered user will be directed to the learner's homepage. Later user needs to use the external link and registered email ID and password to login.
Thank you for your assistance.
We went through customer support, and were notified that tracking is not affected by setting up external users, so we're perfectly content with the results. Thank you, again.