You can duplex 40" from the bypass tray but that only is speced for up to 216 GSM. I believe there is a tray from BDT that will do 400 GSM 40" long but for that tray you would need to do a huge amount of that size to make it worth it.
Automatically Autonomous Automation
Although the autonomous car is not quite ready, a lights out print operation is something you can do right now if you have a comprehensive Print MIS (Management Information System). The advantages can put money on your bottom line. So what’s your next step?
Link to Article