Thanks, what I’m suggesting is actually the other way around, I’m offering my spare 12 speed chainset for someone else to use as part of an 11 or 12 speed groupset. From what I have read, a 12 speed chainset works fine with an 11 speed chain and derailleurs. I have another 12 speed chainset to use with the rest of my Chorus group.
Actually I was following your CP thread to help decide how to set up the 12 speed group - it’s for my dad’s all-road / gravel bike. He needs 165mm cranks according to his bike fit and I was trying to work out whether to try a Praxis or Rotor chainset, but decided against that partly thanks to your experience. In the end I got another Campy 12 speed chainset with 165mm cranks, I couldn’t find anywhere to buy a complete groupset with that spec, so now I have 2 Chorus chainsets which is extremely annoying!