I get the feeling that this all could be done with <20% of the current code. Can you attach your VI once more, but having typical default values in all controls so we can run it without having to guess. (Change all controls to reasonable values, select them all, edit..make current values default, save VI, attach it once more).
(Some controls seem to contain derived values most of the time. Shouldn't these be indicators instead? Some of your algorithm choices are weird. Why is the inner loop running more and more times, repeating calculations that have been done already earlier (unless controls change. Why is there no way to stop the outer loop? [sec] is not a frequency unit. And no, it does not start slighly before start delay. The point is exactly at the start. You see the linear interpolation where there are no points. That's fake.)