Also wondering about motion blur settings. The Manual
references multiple options on controlling it through the PBR Render Target, but there seems to be duplicate options (According to the manual, the "Time" and "Shutter Time" settings do the same thing) and trying the settings out doesn't do anything.
I am thinking of implementing fake motion blur using screen space motion vector data from Unity myself (Similar to "A reconstruction filter for plausible motion blur"
or other postprocess methods), but would much rather have actual motion blur through the path tracer itself.