Diabetica Daemonicus affects the maturity time (reducing it from 20 to 19 hours), however, the total ripe time stays as what it was without the upgrade. Both Stevia Caelestis and Rigidel reduce the entire process by an hour, so the lump keeps falling an hour after riping.
By logic, either all upgrades should only reduce the affected part, or everything down the line, but not that one does the former and another one does the latter. More specifically, by physics, only the latter applies: these processes aren't independent. You can't have a ripe lump without a mature one or a falling lump without a ripe one, and each process has its own base time to work. If DD reduces maturity, it should reduce the entire process by an hour, which it currently doesn't.