How to make sure that the program is really looking for keys? I got the impression that she was missing keys.
Yeah, i have afraid this same. You cannot check this in any way. You can try to search low difficult prefixes , but in sum we don't know all time that this all prefixes was dumped from selected range. I have more than 50% obvious that this app is not working without any issues.
This is probably why the developer did not add a search for a range of keys. so that it would be impossible to track the correctness of the search for full addresses, and not vanity prefixes.