No problem. People have been “over-forking” bikes for years. I mean, technically every suspension fork on a hard tail “over-forks” it. The general rule is that 20mm of travel change is equal to a 1 degree difference in geometry. Thus your Stance will become a degree slacker at the head and seat angles. A slacker head angle is almost always better for descending and I think the changes to the seat angle will be barely perceptible to you.