Since recently acquiring the car, a 2013 Yeti 1.9tdi, I've been using a 20% bio blend and have driven 2600 miles so far without mishap.
I've started using the VAG DPF app to keep an eye on the regeneration and, reassuringly, can see when it takes place.
I've ordered my first supply of Oilsyn CarbonCode DPF and Turbo Doctor Cleaner and will add some to my next fill - which I think I will increase to a 30% bio blend.
"Bill", on here, has been blending for some years and has been kind enough to pass on his thoughts and experience.