If nothing is being interpreted or filtered then what are all the OK and ERROR responses immediately after the connection is established? These are in response to something. This is from your output:
AT 13 6 //As soon as the device was paried it output the below
OK
AT 13 9
ERROR
AT 13 6
OK
AT 13 6
OK
AT 13 18
+XAPL=iPhone,7
AT 13 6
OK
AT 13 6
OK
AT 13 6
OK
AT 13 6
OK
AT 13 9
ERRORSection 4.2 of the HFP profile standard defines a number of commands and responses that must happen on initial connection before the device is considered to be in service. These include AT+BRSF, AT+CIND=? (the one I care about) and others. The fact that we end up with a usable HFP connection means this interaction successfully occurred between the BC127 and the phone. It still looks to me like the full responses to these setup commands were passed through in firmware 6.0.16, but not in later versions.
In your example, you send at+cind? and get a valid response. To know how to parse this response, by definition we must previously have received a response to the AT+CIND=? command which returns the format for parsing the +CIND: response. Is there some other way to get this information from the BC127?