For our Nudura build, we screwed directly to the 8" c/c plastic webbing in the ICF - yes a pain for metric boards, but nothing's fallen off 😉
I posted a a video and photo of hot knifing the channels and fitting plastic conduit (although if you pay a little extra for the low smoke cable, no conduit is required)
https://forum.buildhub.org.uk/topic/38949-fitting-conduit-in-eps/?do=findComment&comment=558991