I reopened Issue #2 this morning as I had a "eureka" moment when it came to resolving part 3 of the issue. Now, providing you use the DPDiscover suggested "hostname" and "description", it should change the "protocol" column entry and "Add" button to the word "ADDED".
Works for me - if it's reported as buggy, I'll rerelease 1.51 with the fixes.
I'll remove the "prerelease" indicator either in a few days or when someone else says it works as desired.