Sorry Benoit - I completely missed the point of your original query.
Yes, SP-252 Smart Sockets 'R' us!
The SP-252 has in fact got two actual digits in each physical display so my solution was to make the original smart socket design as small as possible and use two of them per display.
Accordingly, I have a socket for the actual display into which two of my smart socket PCB's plug. These in turn plug in to a back plane PCB which carries the power supplies and micro controller.
My design is for 12 digits using 6 x SP-252 displays and it shows time, date, temp, pressure, humidity and one of 10 user defined strings which are all configurable from a web-gui. The clock syncs time via NTP.
Please send me a PM if you have any queries or are interested in a kit for this design.
- Richard