Its probably still a good idea, kinda like having someone to hold your plane while you crank, but not entirely nessicary. I've charged lipos in excess of 300 times without ever having one even get warm, but thats just me. Most troubles begin when folks push charging limits or a malfunction of some sort occurs, (rare). Kinda like the safty issue of a battery on a gallon of fuel for the pump to pump glow fuel, that one never made a lot of sense to me. Most all problems EL. and otherwise results from human error of some sort, most, but not all the time.
Jamie Strong