Nice Idea and it works as far as to the point where I have the 8bit tiffs (it also works if you just export 8bit tiffs directly from After Effects). The tiffs or pngs always look fine. BUT as soon as I render it as an H264 the ugly steps reappear!
I seem to be making some mistake when rendering it as a an H264. I’m rendering directly from After Effects (tried Premiere too, but it doesn’t make any difference), where I’m using the native renderer which I set to H264, Millions of Colors, Profile Main, Level 5.1 and even 50 Mbps, Multiplexer MP4.