Marlin files on SD, are tuned to my printer ?

Is it correct to assume that the firmware files I have in my SD card, as received from factory, are actually the ones that are saved on the machine?. In other words, after TAZ printer is calibrated at factory, the tuned Marling files are saved to the SD card or are these files generic and not tuned at all for my printer ?

I ask because I am trying to calibrate the bed temp PID. I am going crazy with the bed not reaching the target temp.

The numbers in Configuration.H in the SD card are:

//24V 360W silicone heater from NPH on 3mm borosilicate (TAZ 2.2+)
#define DEFAULT_bedKp 20
#define DEFAULT_bedKi 5
#define DEFAULT_bedKd 275

While the numbers I get after PID calibration are the following: (command M303 E-1 C8 S90)

bias: 82 d: 82 min: 89.50 max: 90.50
Ku: 208.81 Tu: 20.32
Clasic PID
Kp: 125.29
Ki: 12.33
Kd: 318.17
PID Autotune finished! Put the Kp, Ki and Kd constants into Configuration.h


The files on the sdcard are not tuned to your printer- they’re a copy of the models from our source directory.

Then how can i change just one parameter on the firware while keeping the others parameters as you set them when the printer was calibrated at factory?

All firmware for a version are identical, except the extruder steps on a TAZ.

The PIDs are identical for all TAZ printers?