poor video quality with multiple effects layers

I am finding that my video quality is suffering when putting multiple effects over a background, particularly Boris BCC type effects.

I have a moving rippled graduated background , over which is 4 layers of BCC 3D text.

After rendering, the background looks solarised with all loads of artifacts.  Each layer is introducing more artifacts on to the background.

Ahh I thought,  must be compressing each layer introducing compression problems.  but I have set my project to HD uncompressed 10 bit with all renders set to uncompressed in the media creation tool with exactly the same result!

Any ideas?