No you can't use
No you can't since the firmware.bin from aureinand is decrypted. (Open it in hexeditor and you can read 'firm') the file from cakes fw is the same which provides the Nintendo update server and it is encrypted. I read nowhere how and if you could reencrypt it. Only chance to get it is if someone dumped it while it was available. But the only 9.2fw I found is for O3DS. Guess I'm out of luck. The firmware90.bin aureinand provides is the same I dumped from Sysnand but the boot success rate is nearly 0 when using it as firmware.bin.
Cant you dl it from that iso site? From one of the full cia packs?