I can confirm that Forscan now works great for adjust speedo for larger tires.
Running 215/65r16 Geolandars I bumped it up to 2070 circumference and it's bang-on perfect now when compared to a GPS speedo app on my phone. Based on prior threads I only changed the circumference, no other settings.
First time in Forscan was a bit nerve wracking when that warning message came up that said (paraphrasing): "don't do this, you'll brick your car". At least that's the impression I got. Ha!