How do I install the image in EMMC memory?
Just dd it on eMMC over ssh. Currently this is the only way (except for OrangePi 3, where a U-Boot update is needed).
Is this of any relevance: Can't get HDMI out on OrangePi One on sunxi-next · Issue #290 · linux-sunxi/linux-sunxi · GitHub? I know that the issue is about Orange-Pi One, and I have the One-Plus, but the symptom is the same.
Actually, it's not the same. In that issue report you can see reported -517 two times, but in your report it's only once, because second time driver loads properly. If driver mentioned in the issue wouldn't be enabled, then image wouldn't work on any combination of TV and board.
Do you have by any chance 4K TV with enhanced colors enabled? If so, try disabling enhanced colors.