Display MoreHi killianbe,
I don't know this box, so my port may or may not work fine.
Can you please send me more info(product link, link of original firmware)?
However, I recommend you try libreelec 10. As explained in the first post, you can try booting from the SD card by installing the latest version. It's pretty simple, you have to write the libreelec image to an sd card, insert it, and see if it starts.
Regarding emby addon (which I don't know), if it works with kodi it will also work with libreelec.
Let me know
Michele
Thx for message ! 
that's my box : https://fr.aliexpress.com/item/100500562…ayAdapt=glo2fra