Reading various questions and answers regarding Digital Voice and extensions, although I have not got either, I had this thought for FTTC, if practical.
Could you not fit a simple extension socket next to the master socket and remove the extension wires from the master and fit to the new socket. You then connect this socket to the SH2 allowing all the extensions to take whichever phones you want. This being similar to what is suggested for FTTP.
yes that has already been posted but just depends proximity of master to hub location