Unfortunately it is not that easy since it needs a bit of tinkering and probably try'n'error as well.
General building instructions for Armbian are here: https://docs.armbian.com/Developer-Guide_Build-Preparation/
ATM sources for sun50iw9 family (which H616 SoC is member of) are legacy (which comes directly from vendor, so old stuff) and mainline (current 5.15.y and edge 5.18.y).
Since jernejsk's sources are 5.15 I'd suggest to go for "current" branch first try.
Armbian patchset which is applied against mainline sources for whole sunxi family you can find here: https://github.com/armbian/build/tree/master/patch/kernel/archive/sunxi-5.15
Try putting the mentioned patches there after cloning the repo and build it. May fail due to upstream adjustments, patch order, solar winds.... That is the point where tinkering and try'n'error is necessary. Unfortunately I have neither time to get into more detail nor to try that myself at the moment.
With the mentioned fixes applied, happy to report everything works, except hdmi, wifi, and the other 2 USBs (tested not working with added settings in armbianenv). It is quite usable now as a little x display and screen updates seem to keep up as tested using smtube mpv videos.