Just in case this helps someone else (or me in the future).
I'm not sure what these commands do, I don't plan on fully reverse engineering the sequence however the controller sends them to the NAND chip on startup. They don't appear to activate DDR on this chip but they do appear to modify some register(s). The entire sequence probably isn't needed.
By default reading the NAND chip will result in a very poor quality read.
SanDisk v1 RR might show a very slight improvement.
Reading with RB Ignore might show a slight improvement.
Initially the chip will ID as ff ff ff ff or 98 4c 90 a3 76 51, sometimes it will ID as 45 3e aa a2 7e 51 after multiple ID requests (or after this sequence is sent).
My trick to reading it was using the following "After Reset" command sequence in addition to "Ignore Busy". I'm not sure if Ignore Busy was necessary but I used it for good luck, perfect read
Cmd 0x5C 0xC5 0x55
Cmd 0xF1 0xFD
Cmd 0xF2 0xFD
Cmd 0xF3 0xFD
Cmd 0xF4 0xFD
Cmd 0xF5 0xFD
Cmd 0xF6 0xFD
Cmd 0xF7 0xFD
Cmd 0xF8 0xFD