I can't reproduce that. Do you have a simple example scene?
What versions of Maya and MtoA?
debug-scene.zipHi !
My scene is using reference. After making a test on an imported reference file, I still have that behavior, see the logo on the drone body that should not be blurred.
I'm on Windows 10 pro
Maya 2018.1
mtoa 2.1.0 - 1bdea080 (master) Arnold Core 5.0.2.0
kick --help returns:
Arnold 5.0.2.0 [716426a7] windows icc-17.0.2 oiio-1.7.17 osl-1.9.0 vdb-4.0.0 clm-1.0.3.513 rlm-12.2.2 2017/11/08 19:29:47
Thank's for your help.
pierre