I have 4k source material from three cameras. I know the output will be 1080p for Youtube. When working in FCPX is there any difference in final product quality between setting the multi-cam clips and project to 1080p for the editing session OR setting them to 4k and as a last step rendering the final product to 1080p?

Thanks! This is what I determined from minimal testing but I figured I would ask here as well.