[stevesklar]

With the ligature in the middle behind the "break" then the reed would get "bent" and cause playing issues as the reed will then require the embouchure to squeeze it shut to play kinda "normally"

I'm not familiar with Tone Edges but I wouldn't see how that would be normal.

 

[stevesklar]

I believe this is one of the machined tables methods that would create concave tables (there's different machining methods, plus more manual methods).
I have it and others I'm putting together on various past methods of mouthpiece manufacturing.
You have to keep in mind the wear of the abrasive wheel and any potential heat even though it is liquid cooled.

 

[stevesklar]

I can't recall who it was, but there was one or a couple custom mouthpiece makers who would put a horizontal small concave section. Thus one knew where to place the ligature, and to know not to get a lig that put a singular horizontal "plate".

I have an earlier video (somewhere, hopefully .. i think 1998ish) that showed a more crude method of cutting the table and rails. It was less swoops back and forth, which would have more pressure and heat to the scenario.

 

[stevesklar]

On can find arguments in both sides.
This is from Tom Ridenour's book where he just states that concavity is okay as long as it's not excessive.

THE REED TABLE
There is some debate about whether the reed table should be completely flat, or whether it should have a concave area (as we find in Vandoren and many other machine faced mouthpieces). This is, as far as the author can discern, a rather subjective debate and there are claims on both sides of the argument for this, that or the other advantage. In reality, however, little can be proved conclusively and demonstrated consistently. Certainly fine mouthpieces have been made both ways. However, the author believes that it can be said rather objectively that if a concavity must be put into the reed table that it should not be excessive; excessive being define as the concavity extending above the bottom of the mouthpiece window. Such an extension invites the reed to leak on the facing, and a reed leaking air on the facing has about the same effect of a pad leaking on the clarinet itself: a bad effect on virtually every aspect of sound and feel.