Can't get LE to boot on my Amlogic S905x

Have a read here: https://wiki.libreelec.tv/hardware/amlogic

No idea, perhaps the LE 9.2.8 image that dtech maintains. The last official vendor kernel image was LE 9.0.2 which is no longer maintained or supported. The images are still downloadable but you're on your own for install/boot support.

Quote from tecc

Now I want to install LE instead to finally settle on the best distribution for me. Unfortunately unzipping the generic box image to the SD card and booting from it did not work.

You don't need to unpack it, just write the image to an SD card, but there are additional steps required to boot. The description in the link sent by chewitt includes everything for the new versions.

Quote from tecc

Thanks, but what older LE version should I use with my box should I still like to have 'HDR to SDR tonemapping'?

This definitely works under the community release I maintain (LE-AML 9.2 LTS).