Use the simplify part option before exporting

this should smooth out everything in to nice arcs

go to - database-fittings-pattern switches and tick the simplify part check box

settings for this feature can be changed from the installed machines setup section or from the profile section in Opus

I have never changed these settings but on 2018 version of Cam-Duct the simplify part option seems to have some serious glitches

2017 version works great

hope this helps