Raspberry Pi is actively preventing enthusiasts from upgrading soldered memory to a larger configuration even when the replacement chip is technically compatible. The company says the restriction is intended to discourage unofficial high-capacity resales.
You can just use the Armbian flasher. I have an orange pi 5 plus and a Radxa rock 5-itx, and that’s what I’ve done with both.
you can also use the raspberry pi flasher, ironically.