Is the brake switch somehow able to impact acceleration?

Agree, but if it is as simple as adjusting the brake switch (which we validated by "holding the brake in position with left foot"), then I would just as soon save a trip to the shop. I am looking to see if there is a logic, such as ABS, or Cruise Control, etc, that uses the switch input as a part of the logic. If no answer, I will be taking it to the shop.

Well try adjusting the switch to see if it helps! I am sure if the brake lights are on all the time it has to effect performance. Especially after that Toyota fiasco!