For Libreelec don't use Rockpi4/dev/usb-install - Radxa Wiki. for flashing the emmc. The used rock 4b+ I got seems to have some issues and making a working sd card was hit and miss. Mainly miss. The process is great for erasing everything but not installing Libreelec. Use AndroidTool_Release_v2.71.zip. as you would with the instructions in the WIKI for the latest rkdevtool. The rkdevtool will give you all kinds of errors like "switch failure" and the LBA will be disabled. you won't have these problems with the androidtool.