i2 to X2 conversion question , reflash question

[thrasher187]

I have a Segway X2 that I bought years ago and was in the gravel getting my garbage can and it gave the frown face and shake so I tried to step off of it and miscalculated the Dismount and the handlebars smacked the ground killing it. Very light fall, I couldn't believe it ruined it. I was getting error code e042. This was about 10 years ago and no one had any idea what those codes meant back then. I bucked up and bought the special box and shipped it back to Segway with a set of I2 tires with it that we used it to move it around the house to keep it on the charger. When it got to the Segway Factory they declined to diagnose it because I had shipped the wrong tires with it. What a waste of time and money. So it has sat for years. Batteries became effective. Then recently I bought a used i2 . It needed batteries so I bought a set from AliExpress the 5.2 amp hour version. Great experience. Highly recommended. Now I have a working i2 that I put the X2 tires and fenders on, but it does not like to go downstairs or sharp turns on loose ground. Gets the frown face and Shake much easier than the X2. In my searching online I found that the X2 has different programming in it. A 3 second delay before becoming upset.My question (sorry to give so much backstory) is what part has that programming in it so I can switch it over? Is there a specific board that has the programming or would I need to swap the entire electronic system over? Also someone had told me at one point when I replaced the gyro in my X2 that it needed to be reflashed to work properly and I didn't have it reflashed. Is that a real thing or did someone sell me a bad gyro setup and it will work with another gyro? Possibly the one from the i2?
Recap ;
Question 1) where is the brain or operating system located?
Question 2) do I need a reflash after swapping parts?