I have an Amiko A9 Blue TV BOX currently with Android 9. This box has Amlogic S905X3 (A55 64bit). These test images like 'LibreELEC-AMLGX.arm-11.0-nightly...' are compatible with this harwdare
There's no dts for that specific box, but they're all much the same so you can try the following dts:
meson-sm1-h96-max.dts
meson-sm1-x96-air-gbit.dts
meson-sm1-a95xf3-air-gbit.dts
Note that you'll need to disable hardware video decoding (and CPU decode) on an SM1 box; the drivers were written for older GX devices and need major work to make them compatible with newer hardware. Anything @ 1080p should be fine but forget 4K. For that reason CE is still a better option than LE on SM1 devices.