devinfo is missing information on Google Pixel 4a

I am trying to convert a non-JP Google Pixel 4a into a JP Google Pixel 4a by changing the model numbers. After flashing the latest stock firmware (Android 13) sourced from [the official website](https://developers.google.com/android/images) , I installed [Magisk v29.0](https://github.com/topjohnwu/Magisk/releases/tag/v29.0) and rooted my Pixel by following [this guide](https://thedroidwin.com/root-android-magisk) . [Rooting using Magisk] 0. Enable Developer Settings 1. Enable USB Debugging 2. Enable OEM Unlocking 3. Unlock Bootloader

fastboot flashing unlock

4. Extract boot.img

unzip sunfish-tq3a.230805.001.s2.zip
cd sunfish-tq3a.230805.001.s2
unzip image-sunfish-tq3a.230805.001.s2.zip
cp boot.img /run/user/1000/gvfs/mtp:host=***/'Internal shared storage'

5. Patch boot.img 6. Boot using patched boot

adb reboot bootloader
fastboot boot patched_boot.img

7. Install patched_boot using Magisk Now that my phone is rooted, I accessed protected system files to overwrite using [this article](https://thedroidwin.com/how-to-enable-osaifu-keitai-in-non-japanese-pixel-devices) . 1. Enable root access

adb shell
su

(Tap 'ok' on Pixel screen) 2. Extract devinfo.img

dd if=/dev/block/by-name/devinfo of=/sdcard/devinfo.img

3. Copy devinfo to PC

cp /run/user/1000/gvfs/mtp:host=***/'Internal shared storage'/devinfo.img ./devinfo.img

4. Open the file using the hex editor

ghex devinfo.img

I am supposed to find my phone's model number and replace it with the Japanese version's, but all I see is 16 bytes corresponding to "ANDROID-BOOT!..." That's literally the only thing in the file. Is this method not universal for all Pixels? What went wrong?