I'm new to photoshop and recently learned about quadtones. it seems we have to use 8 bit to access the function. Is there a reason for this? I'm probably wrong, but wouldn't a 32 or 16 bit produce a better quality image, or because we've taken out the color information is it just not necessary?
As, to the best of my knowledge, pretty much all commercial print devices work with 8bit the point may be somewhat academical.
But especially if the Curves you use are extreme and the original image is available in 16bit or as RAW data you may indeed get better results from applying the Curves in 16bit.
You can do this if instead of using Duotone you create Spot Channels manually.