Yes, it is possible to manually flash the EEPROM with the intrinsic values of the first flashed camera. The intrinsic values you need to get from the first flashed camera include the camera matrix and distortion coefficients.
To get these values, you can use the Calibration Reader API code provided in the Luxonis documentation. This API code allows you to read the calibration data stored on the device over XLink, including the camera extrinsic and intrinsic parameters, along with other calibration values written on the device (EEPROM).
Once you have these values, you can use them to manually flash the EEPROM on the other cameras. Examples for flashing the calibrations: https://docs.luxonis.com/projects/api/en/latest/samples/calibration/calibration_flash/ (alternatively, you can just load it on the device - for testing purposes, to see if the calibration is okay)
Please note that while the intrinsic values might be the same for all cameras of the same model, the extrinsic values might differ depending on the physical setup of each camera. Therefore, it's recommended to calibrate each camera individually to ensure accurate results.