We're working on getting new measurements (and maps) made, but I would guess the maximum distance is probably 500-700 feet longer than before. DGCR puts the distance at 6327 feet, I would guess the new longest possible setting would be close to 7000 feet.
Although, since Shawnee Mission park mostly is home to recreational players (beginners, families, etc), the course will usually be set in some kind of compromise between long and short.
The main problem was that the course has been stagnant over the last couple of years, few holes even had more than 1 pin placement, and those that did were rarely (if ever) moved. Now that each hole has 2-3 usable placements, we can move the course more often than before, on par with the other quality courses in the city (Rosedale, WW, Swope).
So anytime you play SMP, you can expect to see a good mix of short, middle, and long placements through out the course. It will never be set all short or all long. Play again in a couple of weeks? Thing should still be mixed well, but it will be a different mix than before.
On another note, I would like to thank Bill Maasen, Superintendent of all of the County's Parks and Golf Courses. He has been extremely eager to improve the course, and has put forth a lot of the County's time and money to make it the best it can be. All of us disc golfers want these courses to be as nice as possible, but it's always great when the local Parks Department shares our enthusiasm. He (and his son, Brett), play the course as much as anyone, so it's not surprising how excited they are to help.
If anyone has any more advice or thoughts about how the course can be improved (or about the newest additions), please let me know.