It’s working now on nightly ng builds. I have a Vontar X3 S905X3 rev c. Audio out is via 3.5mm AV socket to soundbar and all is great. I did check with the stable ng build but that didn’t work, so you do need a nightly. I’m using CoreELEC-Amlogic-ng.arm-9.2-nightly_20200506-Generic.img but I think 202000503 worked as well.
Actually if you follow the guide for " How to configure IR remote control" and then How to configure IR wakeup code
and use hk1-x3-vfd.conf for vfd then everything works really nicely. The microSD slot read/write speed is pitifully bad even with microSD Class 10 A1, actually unusable as everything in the UI stutters & lags, but the USB 3.0 port with a good USB 3.0 stick is fine. I’m using a Sandisk Ultra Fit 32GB. I get about 1/3 its rated performance on the Vontar but it’s enough.
I got the box yesterday morning and we had a good hard fight. Now it is compliant