I'm sorry but I don't understand COTS, LCO, NCA, NMC and actually I am confused.
Since you seem to know your stuff, let me rephrase my question: why should anyone use LiFePo batteries instead of LiPo batteries, giving the cost and (apparently) the same need of a similar protection circuit (that many LiPo have integrated in the case anyway)? Is it just for the reduced flammability? I mean comparing, eg, the same high quality brand in LFP and LiPo
Sorry, I try to avoid abbreviations but sometimes use them anyway.
COTS = commercial off-the-shelf.
LFP, LCO, NCA, NMC = lithium iron phosphate, lithium cobalt oxide, nickel-cobalt-aluminium, nickel-manganese-cobalt, different li-ion cathode chemistries. Anode is always carbon in some form (graphite, for example), recently also silicon being added seems to finally work out.
Do note, "lipo" does not exist. It's all li-ion. We professionally call different
form factors: prismatic, cylindrical, or
pouch. Since a really different thing called "lipo", with completely solid electrolyte, failed to emerge in 1990's, but the
name was too good to be forgotten, the term was later picked up for reuse by
marketing teams just to describe the pouch form factor.
So "lipo vs. lifepo" is just completely nonsensical. LiFePO4 (I like to say LFP instead) can be prismatic, cylindrical, or pouch as well, it's just the form factor.
Your question, why would anyone use LFP, is a good one. It has potential for better safety (which needs to be realized by not wasting it by lacking in safety otherwise); it also uses no cobalt which is an expensive conflict mineral. It seems to me, almost no one is using LFP, the energy density is just so poor and this also translates to cost, even if the materials are cheaper, you need more of them. It seemed like a good idea in early 2000's but picked not much commercial interest outside China, and even within China, it's mostly used by fairly small players. Also, the amount of cobalt used by "traditional" li-ion went down significantly when NCA and NMC superseded the classic LCO chemistry during the last decade or so.