Hi Ned,
I looked this up online, and you can read about this setting in the 3880 manual if you have it on hand (Page 52):
https://files.support.epson.com/pdf/pro3880/pro3880ug.pdf"AccuPhoto HD2 for any type of photographic printing. If you are
printing 16-bit color images, select 16 Bit Output for the most
accurate transitions and gradations."
So you would check that box if the image you are printing is 16-bit. In this case, the Qimage One pipe line is 8-bit, even for 16-bit source images. So that box should NOT be checked for use with Qimage One.
As far as resolution, use the highest resolution for printing smaller prints, where they will be viewed closer. For very large prints which will only be viewed at a distance, you can use the lower resolution settings, which will reduce processing time to print.
Andrew