Ligno Trend builds the wall with cross-laminated timber. So solid. We used cellulose as insulation material. Recycled material, low CO2 footprint, walls become a bit thicker, better sound insulation.
Are you then at Kielwein? We also looked at them last week. I think they are the only ones using cellulose. However, I was informed that the insulation can lose about 10% due to moisture in diffusion-open construction. Whether that is true, I don't know of course.