It's not the melt pool that's the problem, I think, it's the oxygen lacking when you get further down in the jar, on the TALLER ones (16oz, 22 oz, 26 oz, etc), with flames that begin getting smaller and smaller. I've tested LX-10's and you are right, after a couple of burns, they are fine, but, they absolutely don't work once you get further down in the jar. They aren't big enough. I've also tried going DOWN in size, as some have suggested that the smaller sizes tend to require less oxygen, and, while that makes sense, in practice it didn't work. I have found that the smaller the wicks, the less likely they are to work in this scenario.