Believe it or not, after several exchanges with a Level 1 guy at the XPAL Tip Finder Service, in which I've been expressing how well-suited the XP8000 is for use with portable audio gear and how readily many of us will drop 100 dollars for the sake of sound quality or convenience with our expensive, power-hungry amps and headphones, he sent a reply today saying that his Developers have agreed to create a prototype cable that's basically a WI15 with a permanently attached tip of the correct size for the Stepdance.
He says it may take "several days". Then they will ship it to me and let me test it. If I report that it works well, with no issues, they will then consider offering it via their XPAL Tip Finder database, where it would be a special part number (WI15-S?) dedicated for the purpose of using an XP8000 or XP18000 to supply 15V to the Meier-Audio Corda Stepdance (or any other 15V device, of course, that requires that size tip).
Apparently, they have a long history of satisfying their Free Tips for Life customers, which includes prototyping and then manufacturing one-off tips or cables for odd devices. In other words, they don't seem to be too very concerned about how many Stepdance owners will buy an XP8000 and order the special cable, because they are all made to order at first and if another device comes along that can use that part number, the new device or devices get matched with that same part number in their database.
Tick, tock, tick, tock...
Mike