Your website just says:
On 2023+ ChromeOS devices using a Gen2 CR50 security chip (aka
Ti50), there is a new feature where the CR50 will verify the RO portion of the AP firmware at boot. If you want to flash custom firmware, you must use the CCD method above to disable firmware write protection, regardless if the device supports disablement via battery disconnect or a jumper as well.
So when the script failed to re-enable sofware write protect I had no reason to believe this would have any effect on AP RO. The website only says that RO portion of firmware is verified, not the state of write protect registers. Also the linked documentation from Google does not mention this.