Ok this image booted into UEFI:
https://solid-run-images.sos-de-fra-1.exo.io/LX2k/lx2160a_uefi/lx2160acex7_2000_700_3200_8_5_2_sd_ee5c233.img.xz
I need to work now so cannot further test. But after work I will try to write UEFI to SPI and boot from there. But I guess for that I will need a U-Boot image that works. According to your instructions here: