After having used another, similar, extension, I believe that DT Register is a significantly better extension, and one that works very well for my needs.
I have found the developer extremely responsive to questions and there is an active support forum for those with questions and suggestions for future improvements.
For me, the product worked "straight out of the box" ... but I have chosen to make some minor cosmetic amendments in the back end to make it even more suitable for my needs.
Thank you for a great extension. I predict it will only get better in the future. :)