Oh I see, you're using the EG4 just to top balance. I have a DC power supply that I was planning on using for this (though much less powerful and will take a little longer even for my 100Ah pack). But my plan is to do the same: bring them up to about 3.55V in series then do the last bit in parallel.
But my application is a little different, it's not for solar. I'm putting these cells in an electric ride-on lawnmower (replacing old AGMs with LiFePO). And so I'm looking for an everyday charger, not just for top balancing. Do you think it's ok to routinely let the Overkill to set the top voltage?
Thanks for the quick response!