@johans In the midst of the Holidays, found difficulty getting in touch with them. Was hoping to find an answer on the forums in the meantime.
Got in touch with them today, for future users with a similar question: Grey Mirropane reflective material is attached on the frontside of the glass. So mounting to the backside with 3M VHB is a go :thumbs_up: Asked for alternative mounting materials, and they said 3M VHB is what they use as well.