Keep in mind that there are 5 different 'grades' of FE1, FE2, and F41. FE1'* thicker springs overlap the low end of FE2 (but the ride height differs, the FE1 being 1/2" higher), and FE2 overlaps the lower end of F41.
The springs (FE2) on my SSEi are in the lower end of the F41 range. So you CAN get FE2 springs that ride the same, or are damn close in performance. Particularly if you use the ELC function. It tends to stiffen up the FE2 a bit, and is an integral part of the FE2 design. An FE1 car converted to FE2 will not handle the same unless the ELC is included in the swap.