Also see the option near the bottom of the "results" tab of the Advanced version, "FIRECalc will search for settings that will get a success rate of as close to ___ % as possible (usually within 1%) by changing... [ ] how much you spend each year. This will do something close to what you are trying.
Often uninformed, seldom undecided.
Twenty years from now you will be more disappointed by the things you didn't do than by the ones you did do. So throw off the bowlines. Sail away from the safe harbor. Catch the trade winds in your sails. Explore. Dream. Discover. Mark Twain