I recently got a RockPro64 board, which at the moment has very little software to run on it. I was pleased to see the other day that there is now a LibreElec build for the board. I've been checking test.libreelec.tv for the past few days and, yes, the nightly build is there each day. However it's always just 21MB in size and when you download and open it, it says "unexpected end of archive".
I've managed to build the image myself but I've not yet had a chance to try it. My first attempt at building it a couple of days ago met with failure.