Won't happen. I talked with the Browning guys about a sxs, as did a couple other outdoor writers, back when they brought out the Cynergy. All the Miroku workmen that built sxs have retired, and they no longer have the tooling. (Note that SKB is also now out of the sxs market.) Agree it's a shame.
Friend of mine bought a SLNE, Miroku Model F, a couple years ago. Essentially a BSS Sidelock, but with extractors. Previous owner had installed thin-walls. It's sitting at the Cabela's store in Owatonna. Has been there for some time, and I'm guessing a reasonable offer would take it home.