Very nice article. One comment: another source I've read opines that the Mainz was abandoned not just because of the greater cost of manufacture, but because of too many broken tips. That blade is really designed to thrust, and when used to cut, especially if the cut was with the tip, the tip would often break. The Pompeiian, with its short squared off tip, did not suffer this difficulty,

Yes, IIRC Peter Connolly made the same observation as regards the Mainz, and especially the Fulham. I don't know if there's any evidence to support this (ie actual Mainz and Fulham blades found with such damage), but I think the theory has some basis. Those long, pointy tips do look rather fragile....
I think Connolly also theorized that since the armor-piercing capability was not needed as much against Rome's usual opponents during the Imperium (Germanics and Gauls) . so the long tip was abandoned as unnecessary.

I hypothesize that physical evidence will likely never be found for the following reasons: (1) antiquity, (2) who would keep a broken sword? and (3) isn't it reasonably probable that the steel from broken swords, being a relatively rare comodity, would get recycled?