I want to implement a easy upgrade OS mechanism on our custom developed board, we are using imx8mp processors with yocto kirkstone. I just need to be upgradable locally, with an usb stick.

I can see a comparison here: https://wiki.yoctoproject.org/wiki/System_Update
All options are quite impressive, but also quite overly complicated, I expected to have something already integrated in the BSP, but it’s not the case.
My choice fell to swupdate, but still kind of hard to setup.
Tracking my progress here
I can see this question have been asked many times in the past, and I wander what’s currently the best and what should I use, and how.
I found this quite impressive, for example: https://developer.toradex.com/torizon/in-depth/ostree/
but I am not using toradex, and seems quite a burden to do all the job