As Saqqara has shown (see video) there really isn't much customization you can do with the built-in 3CX wallboard. I wish I could offer more helpful information, but there simply are no options other than building your own wallboard.
There are only two possible sources of data for building custom wallboards, (1) parsing the CDR data that 3CX can optionally create. This approach is not live because the CDR files are only written when the call is disconnected. The other option (2) is to subscribe to live events using the 3CX Call Control API.
Some people have been known to access the PostgreSQL database directly to build their wallboards, but this is strongly discouraged and could get your 3CX flagged as unsupported. Do not use this approach! To further discourage you form this approach, be aware that it appears 3CX caches writes to the database. As a result, you may have to wait several minutes for the data to show up. This data is not necessarily "real-time".
If you need a custom wallboard, we can help. We have built several different wallboards you can choose from, or we can build a wallboard that meets your specific needs.
I will say that building custom wallboards is one of the more challenging projects we have implemented -- especially in high-volume environments. We build our wallboards by subscribing to live events using the 3CX Call Control API (we don't access the 3CX database or CDR files) so our data is real-time.
