You might want to also NOP writes to the flash chip. Commands sent are only valid for the Intel E28F128J3A chips:
Read Array SCS/BCS 1 Write X 0xFF 1
Read Identifier Codes SCS/BCS = 2 Write X 0X90 Read IA ID 1,7
As for the J3 commands being written, they are ignored as they dont have any meaning to S29GL devices.