I think it's a great idea, and necessary if TenX actually wants to be a usable solution for any mainstream adoption.

Even considering the gains one could accomplish by doing more of their disposable income spending in crypto versus fiat, the former's volatility would make every purchase a dice throw unless something like this does, in fact, get implemented.

What mainstream person wouldn't be immediately turned off by a chocolate bar effectively doubling in price at the register, just because their coin of choice happened to dip at that exact moment?

Long-term overall benefits or not, they're likely to balk and revert back to fiat as soon as the novelty wears off, and mainstream adoption is what TenX is banking on.