[Google Pixel 6] Jon8RFC:
Factory image flash is what I'm comfortable with and have been used to, for many years. There was probably a solid reason why I switched from OTA back with the original Pixel, but I can't remember what that was.

These days, I don't like ever booting without root and dealing with some nuisance like "device not certified" or some unnecessarily sensitive app getting a whiff of something out of sorts.

Plus, it's handy for situations like I'm experiencing, which is that I want to use a custom kernel, but for some reason a small group of Pixel 6/Pro owners can't boot with a custom kernel. I have other batch files handy to very quickly flash back to stock kernel patched with magisk with minimal intervention by me, and I'm already sitting at my computer.

I don't like to do major things away from my computer, either. If it's a totally stock phone, sure, because updates are tested in stock scenarios. Updates probably aren't nearly as rigorously tested with Magisk (but I bet at least one person tests it) by the Android QA team, and maybe even no automated emulator tests with Magisk exist despite topjohnwu working there. It's like having a heavily modified vehicle. That's a weekend car, not a roadtrip car when some "you're about to spend $4k" light starts flashing because the different ignition timings don't play nicely with the misrepresented, junky, old gas filled up at "Pete's Friendly Gas Station", but a daily driver wouldn't mind Pete's gasoline. Once something is modified, standard usage scenarios often no longer apply, because the rules have changed even if the changes are "improvements".

It's slightly less convenient than sitting on my couch applying an OTA while watching The Office, but I feel better when the infrequent situations arise when something goes wrong, because I already have every single thing up and ready that I might need.

The download took 48 seconds. The flash-all.bat process is 1minute 33seconds long. Timing the rest is more difficult and subjective, but I'd guess not more than 1.5 minutes, but some of the factory image process is done with the OTA process I would think, like the patching boot.img, rebooting, flashing, rebooting again, which takes longer when it's not done in one swoop, because of the phone booting up. Booting up my computer isn't a hindrance, either, with "alexa, desk on" from my potato-supporting couch. I haven't had that "updating" thing for the past 2 month's updates, maybe 3. I didn't know that the Google-flashable thing somehow prevented that from being necessary, but that's handy if so.

My process is shorter and requires less intervention, in comparison:

Download latest factory image (bookmarked page)

Extract files

Edit flash-all.bat to remove the -w flag

& to flash magisk patched boot.img, (I just copy & paste from my prior flash-all.bat)

Drag & drop new boot.img to phone

Patch new boot.img in magisk

Copy patched boot.img to the same folder as flash-all.bat

Reboot into bootloader

Run flash-all script (no further steps)

Here's my edited flash-all.bat:

PATH=%PATH%;"%SYSTEMROOT%\System32"
fastboot flash bootloader bootloader-raven-slider-1.1-8244211.img
fastboot reboot-bootloader
ping -n 5 127.0.0.1 >nul
fastboot flash radio radio-raven-g5123b-97927-220225-b-8226700.img
fastboot reboot-bootloader
ping -n 5 127.0.0.1 >nul
fastboot update image-raven-sp2a.220505.002.zip --skip-reboot
fastboot reboot-bootloader
ping -n 5 127.0.0.1 >nul
fastboot flash boot magisk_patched-24300_pixel6_may22.img
fastboot reboot

echo Press any key to exit...
pause >nul
exit

And a comparison of before and after (click for full size):