I don't get it.
You drill and tap a hole in your bowl, then drill and tap a hole in the engine side of your carb?
I think its a cool idea.
The only time I can image it being worth the trouble would be on something like a sha where you don't have any tuning capability besides the main jet and the airfilter,
Other than that you have needles and mixture screws that can be used to make your mixture proper.
And as far as not needing to rejet after break in, if you only ride late spring through early fall thats probably true. Its those winter months that make rejetting a must.
Up here in the Wisco we have temperature fluctuations of like 150 degrees over the course of the year. It goes from like 105 in the dog days of summer to like -25 in the winter deep freeze.
I don't ride when its that cold, but I will ride when its like 35. Thats still like 70 degrees difference.