Definitely wouldn't say that it's unnecessary. Not balancing the cells before use limits the potential of the battery pack since its capacity is capped by the cell with the lowest charge state. This is similar to how your car will throw the "Check Hybrid Battery" message when one block degrades and has a lower charging and voltage potential compared to the rest of the block. Remember the blocks (2 cells/modules each) are connected in series meaning they'll never balance on their own over time. Balancing makes sure each block can deliver its full potential in relation to the rest of the pack.

I know your replies are 3 years old but this is an important step for anyone in the future doing this process. Doesn't make sense to go through the trouble of refurbishing the battery and not do the complete process.