large px sized comp not rendering in after effects
So really wanted to be able to export from afx uncompressed but could not find a codec that would allow export of such a wide pixel width. I tried 'animation', that did not work for me. If you know of another codec that does work at the larger widths, let me know!

Anyhow, I ended up just exporting with H264 codec / compression which works even with the huge pixel width. Then used an older version of Apple's Compressor to reexport that to uncompressed AVI. It looks fine.