(EDIT: Just to be clear, and which is also mentioned in that post: unlocking the bootloader will reset the device. If your device is already unlocked though, you will be able to keep the data.)
Of course, I would just advise to switch to LineageOS directly, since Google has stopped providing security updates for the Pixel 4a already in August 2023. I've run LineageOS for years on the Pixel 4a and it has worked pretty much perfectly for me:
I'd also be interested to know if a Google Camera app installed post-facto to LineageOS is compatible with the remote control & viewfinder of the Pixel Watch.
Well, they are good enough for me, but to be honest, I'm not particularly picky... As said in a parallel post, you can get GCam in APK form (I run LineageOS without GApps) but I hear it's a bit trial&error to find one that works and I haven't bothered.
https://xdaforums.com/t/undo-the-january-2025-update-without...
(EDIT: Just to be clear, and which is also mentioned in that post: unlocking the bootloader will reset the device. If your device is already unlocked though, you will be able to keep the data.)
Of course, I would just advise to switch to LineageOS directly, since Google has stopped providing security updates for the Pixel 4a already in August 2023. I've run LineageOS for years on the Pixel 4a and it has worked pretty much perfectly for me:
https://wiki.lineageos.org/devices/sunfish/
Android 15 (LineageOS 22) was just released for it.