Auto levels on a DNxHD render will be read natively as 16-235 in Avid and 16-235 will be monitored as full range by default out of Avid. That means you will see the same in both programs. I'm not sure how this works in Premiere because of that the timeline is set up in RGB (1-255), the opposite of Avid. If it reads the DNxHD renders as full range you will be fine. Do a quick test with the different output level options.