Hi,
I would like to recommend or suggest if you could include an option by adding new extensions, which could allow you adding more than one extension at a time. For example: if one must add extensions from 700 to 799 then one must do it now for each one seperately. Adding an option "from:to" would save a lot of clicking. Also will be nice when you could also do this for prefixes.
If one has extensions from 700 to 799 and the prefixes are the same, for example 12345, then the whole configuration for numbers will be done in two steps
Regards,
Robert