as im long time archicad user i can say only this...
archicad material assigning and material tool work is complete DISASTER and i can bet it is software with worst material workflow on this planet...
If you ever want to make some quality render, with your control over model and texturing you would use Blender (cos its FREE and one of the BEST around)
Just sit down, learn UVmaping in blender, texturing and it will conect you with archicad better then any archicad exporter
So for archicad exporter
i vote NO
But looking at piranesi
software i will vote YES
! (it could be great if Octane render could render pic as Epix format so that image could be used in piranesi)