Wow, HKM Industry! I am genuinely blown away by this level of feedback. Thank you so much for taking the time to write this masterclass.
You hit the nail exactly on the head. The issue isn't the speed value; it is absolutely the raw distance-based auto-switch firing every frame and wrestling control away from the player. Your breakdown makes perfect sense.
I am going to prioritize your simplest fixes first:
Locking out the auto-switch during deliberate input.
Turning that unused Pass button into a Manual Switch key! That is a brilliant idea.