High breakup tweeters like the KEF LS50 tweeter?

Undoubtably, the tweeter in the KEF LS50 is of exceptional quality (if the hundreds of glowing reviews are anything are to go by) and one of its characteristics that make it so excellent, might be the tweeters extremely high 39khz breakup frequency.

39khz breakup is even higher than most beryllium/ceramic/magnesium/CFRP/etc tweeters and not that far off from diamond, but what's truly impressive, is that KEF has achieved this 39khz breakup not with any of those fancy materials, but with just plain, cheap aluminium alloy. (likely 6061 Al/Mg alloy)

From what I understand after reading the KEF LS50 whitepaper, this is possible due to thier "stiffened dome" technology, which combines an ordinary metal dome with a stiffer, folded metal cylinder.

Just for curiosity, are there other aluminium-based tweeters (DIY available or otherwise) that have a similar, or even higher breakup frequency to the KEF LS50 tweeter?

Or are there other tweeters featuring similar technology to the KEF "stiffened dome"?

(I know of the YG Acoustics BilletDome, but their aim was a hybrid hard/soft dome timbre, rather than raising breakup frequency)