Yes but the problem is the following
As far as I understood, the a905x uboot boots from SD only when the board is reboot in recovery mode
So, if you install Libreelec in internal NAND, you actually are exiting from recovery mode, so uboot will always try to boot from the internal NAND (application partition and not recovery partition where you have the original recovery or where TWRP will get installed eventually).
If it happens that the internal NAND (now containing Libreelec) gets corrupted (wrong, buggy, Libreelec update) then to recover (regardless if you what to reinstall Android or a working Libreleec) you must reboot in recovery again.
But since now NAND cannot boot, you cannot do any "reboot recovery", or other methods except of the toothpick method, but if you don't have the reset switch, you have to open the case and solder a short on the pad...
My doubt is about the entire boot process: in case of TWRP, will it start regardless id we are in recovery or not mode? If so, maybe it can be used to switch in recovery again and boot from a working SD card to recover everything, but I cannot find an answer on this
kszaq do you have any docs explaining in the details the boot sequence of the a905x as implemented in these Android TVs?