Yes I am still interested in development for the newer Hisi boxes. Recently I was even able to re-build the OpenaTV image from the sources for the Dinobot 4K SE. Especially I wanted to find out from where the kernel (sources) come and what about the Hisilicon drivers.
Having these available is important also for creating a LibreElec image for Hisi.
Unfortunately I was not yet lucky to get one of the Hi3798CV200 based boxes. At the moment I try to build the recent Hisilicon kernel (provided in sources for the Poplar board) for one of my boxes based on the old HI3716CV200. And after this I will try to add user space either from OpenaTV or LibreELEC.
We produced Dinobot boxes. Maybe we can work together.