First let me say I enjoy using the registry and appreciate the amount of effort you put in keeping it as up to date as you can. Maybe something can be added that might help cut down your work load?
Can you add something that lets us request slot additions from inside of our edit set pages? Something like the "add from inventory" button we have in the custom set edit page.
Example: Amazing Spider-Man(2018) set currently goes up to issue #46. If I wanted to add issue #47 I could click the "Add from Inventory" button and select issues 47, 48, 49, etc. from my collection. When I hit submit nothing would change with my set at the time, but you would get a request with all the info you needed (Set name, Cert#, etc.). Then you could approve the requested slots and they would be added to the set. If you didn't approve the request then someone could go to the forum and ask why.
I don't know how the back end works for the registry but since you have somewhat similar functionality in Custom Sets I thought it might be possible to add.
Thanks again for all the work you do with the updates.