I'm not defending the brand. I have no allegiance to the brand at all. I've run two of their engines and I have a couple spares of the one I still use. The main attraction for me is the engine costs $45, so if my girlfriend's nephews fry it, it's painless to replace it. I'm just speculating as to the reasons why they designed their engines the way they did.

Put a baby-sock over the heatsink if you want it to run hotter during break-in without leaning the fuel mixture too much. That's like the first thing anyone tells a nitro noob about running in cold weather, and it applies equally-well here. Does it fix the problem that their race engines are too tight out of the box? No, but if it helps the break-in process go more smoothly, then roll with it.