Nice post Argess!

The only thing I would debate you over is the re-breaking in thing. I would argue that once the engine has been properly heat cycled, adding or removing shims, installing short plug, or doubling up on plug washers only warrants a re-tune.

And since you eluded to it in your post...converting to run without a pressure line eliminates the fluctuating pressure, and the varying tune associated with it...
....But that's a different talk show altogether