David Weaver
You're dead on with the wear - I had considered that got no bearing surface near it, but you're correct that it's also increased in focus at that spot. When you use a kanna that's got a lot of wear at the "back stripe" in front of the iron, it can be pretty yucky.

The sanding scenario that I mentioned is only really practical if one already has the setup and has confirmed that it's flat. If doing it instead, for example, on sheet sandpaper on granite, it would quickly become a nuisance.

Wooden (western) planes were generally trued by planing the soles where they were out of true - I think I got my long lap with 80 grit paper to restore metal planes, but it's turned out to be useful for miter tuning and working wooden planes. Without it, I'd have kept hollowing the soles.

Wiley at one point suggested an LN 212 to me and it was the last scraper plane that I let go of because it was so good for scraping the center of dais. I've still got a gaggle of japanese planes and would imagine a phase will come around again sooner or later (I have a bunch because of a rash of buying matched or unmatched unused or little used kanna on buyee - when I see bubbly wrought iron in a ledged dai and a matching cap iron for $60 or $75, it is hard to resist. There is just very little that looks like that that ever comes across the ocean and ends up being junk).