The thing about losses from charge source is they scale with current, so when current is low or zero the losses are near zero as well. It really doesn't cost much to keep most of these voltage sources on at 'idle'.
So like if you had a 24 > 13.8v step down converter on a 12v lifepo4 system, it would be working most of the time but would draw almost nothing when your battery was 'full' and above 13.8v. Or if you used a 24 > 12v model it would only kick in when the battery was nearly empty as thats the only time a '12v' (4s) lifepo4 would actually go below 12.0 volts. The rest of the time it might draw 1, 2, 3 watts just sitting there 'on' and doing nothing.
Also, i agree the charge rate is overly conservative. Most lifepo4 from what ive seen (here and in product listings anyway) will tolerate a .5c charge rate with good longevity, which would be 50a on a 100ah battery. I dont know what the shape of the curve is but it seems like when you charge at a faster rate you are just trading away some cycle life, but i think a lot of these lifepo4 are in applications where they would never die from 'cycling out' anyway so in those situations charging at a higher rate could be considered as costing you 'nothing really'. At least, that's my understanding. I guess it really depends on if you think you are going to put the equivalent of many thousands of cycles on that system or not. Keeping in mind if you did one cycle a day, it would take almost a decade to hit 3000 cycles, and a lot of systems cycle less than once per day at which point you get into questions like 'will i even still be alive by then'.
