Absolute duplicates can be removed but be sure they are totally duplicate. The Cntrlr field indicates whether this is a Controller link record (=1) or a Responder link record (=0). The Cntrlr=1 records (Controller) are those used by the KeypadLinc for controlling other devices. The Cntrlr=0 records (Responder) are those needed by the KeypadLinc to respond to other devices.
The 00 00 00 in the last three bytes of Cntrlr=1 Controller records is okay as these fields have no meaning in a Controller link record. Set button created links may use these bytes to indicate the Cat/Subcat (device type) values of the device being controlled. They are not functional in any way to the operation of Insteon hardware. Do not delete them because they have 00 00 00. In a Cntrlr=0 Responder link record these values represent On Level, Ramp Rate, and Output Unit number respectively for the Responder device.