You didn't read what I wrote earlier...
Forget 2.1 or 2.5... There is VERY LITTLE energy left in a cell once it reaches 2.8v unloaded.
You get MAYBE, AT MOST a HALF of an AH once a cell reaches that plateau.
That equates to about a mile...
Look at ANY discharge curve of just about EVERY LiFePo4 and you'll see what I mean..
The "worst case" scenario of lifepo4 after 2.8v is .25ah and "best case" is .75ah.
Constantly discharging at 2.1-2.5 cutoff WILL SIGNIFICANTLY lower your usable cycles.
To repeat what I stated in another thread..
I have OVER A THOUSAND cycles on my 36v 15ah battery and my LVC I set at 2.8v per cell and to THIS DAY. I still get 14 AH out of that battery setting the LVC at 2.8 per and that's ~92% of "full AH rating" of my battery, even after all of those cycles..
My numbers dont lie...
You seem to think that there is a significant amount of energy between 2.8v and 2.1v.. It just ain't true.