In North America this value really needs to be a "3" or above to collect the CID info. Otherwise the 3102 doesn't wait long enough before sending the call info on to 3CX.
I'm assuming that this provisions the 3102 with a "0"
<PSTN_Answer_Delay_2_ ua="na">0</PSTN_Answer_Delay_2_>
And this (yes) sends incoming PSTN calls through to the FXS jack, which is fine if you don't want to use the 3102 as a 3CX trunk.
<PSTN_Ring_Thru_Line_1_2_ ua="na">Yes</PSTN_Ring_Thru_Line_1_2_>