The chip itself is not great. Its predecessor the EF9345 was only a text video sequencer, and the EF6366 is only a graphics video sequencer that draws text on a graphic screen.
Not suited for new designs.
In Rolf-Dieter Klein's book, Mikrocomputer Selbstgebaut Und Programmiert, page 264, there is some Z80 source code for the EF9364, which I assume is a very close predecessor to the EF9365. German comments.
If I wanted to experiment with this chip I would buy a modern reproduction of the GDP-64 board and interface its bus to whatever other bus I was using, or recreate the Elektor board.