On the Yokos, the OE info was discussed here not so long ago. Essentially one speed rating is OE for Elise, the other for MX-5 ND.
In terms of replacement, I’ll probably also put another set of Yokos on when the time comes. I often use Kumho and like what they produce, although annoyingly the version mentioned above is XL rated which there’s really no need for on the MX-5.