I finally installed PostmarketOS on my Samsung Galaxy Tab 3. It took me a whole day to build only to realize that I was flashing the rootfs to the small SYSTEM partition. Now running on the USER partition with no issues except for wifi that needs some extra configurations in order to work.
The documentation says it is not supported and I have not tested yet. I am trying to get wifi working first. I followed the documentation but i cannot see the “mlan0” device.