MPPT solar charge controller - battery charge current at MPP

[fedimakni]

Hello,
I am currently planning to design an MPPT solar charge controller and i am trying to follow a reference design from TI - TIDA 010042
i am planning to use arduino as the microcontroller for this project.
I tried to learn and make some research about MPPT and how it works but I still have some remaining principle not clear.
I will start by the conditions: I will use 12V battery and my load contains a motor the motor works only if needed otherwise the system has a camera which take some pictures and do analysis ... (variable load)
I have 2 approach for this:
1 - use the same bloc diagram as TI and implement the charging algo in the uC
2 - Remove the charging algo from the uC and add a dedicated charge IC between the MPPT block and the battery.
I am not sure if the second method can work or not (i am currently in the first phase of the design)

Here comes the important question: for the first approach let's take at a given condition the solar panel operate at Vp and Ip the MPPT bloc will try to change the duty cycle of the buck or boost or buck/boost converter to mimic the load which extract the max power (P&O algo) now the panel output Ipmax and Vpmax with that specific duty cycle the DCDC will output a correspondant Idcdc and Vdcdc let's assume that the Idcdc at max condition is 5A and the battery need to be charged at 3A (constant current phase) in that case we need to change the duty cycle to output 3A instead of the most efficient 5A and that let the solar not operate in the MPP region.

Could you please provide me your support to understand better the logic behind it? (I attached the bloc diagram of TI)
Thank you for your cooperation.