The stock spring rate on the 1190 R US version is .55NM which is a large improvement over the 950-990 Adventure lineup which came stock with .48kg fork springs.
They are still on the soft side and can benefit from having the proper spring rate installed. As for the valving, the new 4850 MXTA SPLIT fork design is a completely new design than any previous KTM model.
Both compression and rebound damping circuits are extremely sensitive with this new design, therefore any increase in spring rates should be followed by valving modifications.
We are working on putting something together showcasing the differences between the forks off the 950-990's and the current 1190's. This should be done sometime in the near future when we get a chance to break away from the current workload.