Transmission Not Go Into Gear problems of the 2019 Honda Odyssey

My main issue has to do with downshifting. Since these new vans have no emergency brake pedal to use if all braking fails, I became very concerned when I noticed that the 9-speed revs the motor up going down hill while downshifting. This is to such a level that the vehicle cannot engine brake itself. You absolutely have to hit the brakes because it will not slow itself down. So, when coasting down a 6% and steeper grade with no accel pedal at all. . . . . The transmission does not gear down on its own at all. It will free wheel. Which is fine. So, when the acc cruise is engaged with the minimum follow distance set, on a 6% or steeper grade. . . . . The transmission will sequentially downshift. Upon each downshift the engine throttle is blipped causing the vehicle to speed downhill a bit more. . . . . And a bit more. When you get to the d5 to d4 downshift the throttle is agressively blippled and the van will speed ahead as if to pass. Sometimes speeds will reach 75mph down hill and agressive braking is required by the driver. You then lose your preset acc. . Knowing that I have no emergency brake pedal that I can modulate pressure/braking with the release handle. So. When using standard cruise control set on a 6% or steeper grade. . . . . The transmission will downshift. Upon each downshift the engine throttle is blipped causing the vehicle to speed downhill a bit more. . . . . And a bit more. When you get to the d5 to d4 downshift the throttle is agressively blippled and the van will speed ahead as if to pass. Sometimes speeds will reach 75mph down hill and agressive braking is required by the driver. You then lose your preset cruise control. Knowing that I have no emergency brake pedal that I can modulate pressure/braking with the release handle. This situation has been present since purchase.