Without getting too in depth, factory wire, like in a stock EVOD head tends to be pretty thin, IMO thin wire can't handle too much power going through it, it gets too hot too quickly. So yeah, start low then work your way up, it's much better than starting high and burning your juice and getting a nasty taste that won't go away for awhile. I've only tried one coffee flavor, but I've heard they tend to do well with a warmer vape, mine has chocolate in it too and honestly I haven't found a good setting for it, too high and it burns and gunks up the coil, too low and it simmers... And gunks up the coil. It's possible it's just not a very good juice, hope yours does better.