Anyone using them? I decided to get an inum DID today and I like the concept. 3CX works well (as expected), just make sure you make a Outbound rule to add the required prefix (if needed) from your trunk provider.
The problem with inum is very few providers can route calls to inum number (for most of them this is unknown destination). I was using one number via callcentric (not available anymore), it was configurable as DDI number at callcentric trunk.
Lots of things at one time worked at Callcentric, post disaster they are still struggling to get on their feet. Many carriers (including us) will terminate iNum. On their site you can find a very long list of carriers that do.