There was an inquiry for clay/terracotta rainscreen data on the EC3 community forum site. https://forum.ec3.community/
https://forum.ec3.community/t/clay-and-or-terracotta-material/310
I would add, as I did there, that it may be particularly helpful - though more work - to look at the whole assembly (including rails, clips, and possibly insulation options) as I could imagine that the metal support structure can be a major contributing factor of facade system carbon, and different cladding materials/products would require different support structures. And different levels of insulation thickness would also affect the amount of support structure.