Thank you gary a lot. This did the trick! Now I boot to LEDE from SD card and EMMC as well. I believe it would be useful to add this hint here: https://bananapi.gitbooks.io/banana-pi-bpi-r2-open-source-smart-router/content/openwrt.html.
So partial success so far. Unfortunately I still do not boot the Ubuntu. I moved my ask for help here (believe it is the better thread for that topic than this one):