TIDA-010247: Function of REG2 for cell balancing?

Tool/software:

Hello,

Can you please explain in detail how REG2 is used for cell balancing? I have tagged another post asking the similar question above. (Also here).

For the design I am considering not using REG1 and REG2 of both AFEs. Please let me know how is cell balancing related to REG2 as I was not able to understand from the linked post.

Thanks,
Abhijith.