> (1) The PNG contains an embedded ICC color profile* (likely Display-P3 or another wide-gamut color space),
Why didn't you check? From what I can tell when I did, there is no color profile in the original image so it'll default to sRGB. This really looks like a gamma issue of some sort (see @perching_aix's comment).
Make sure to send me the images that crashed it (support at flyingmeat.com)! I'd love to get that fixed, as I'm not aware of any cases right now where this happens.
A cordite stone will work well against the broiler. But as with any stone, you're going to want to hit it up slowly to reduce breakage. I'd recommend at least 40m heat up to whatever your oven's top temp is (probably 550), then switching to broiler after that point.
It doesn't have to be a WFO (wood fired oven), but you will get slightly different results depending on wood/gas/electric.
I used to have a WFO, but after I moved houses I've switched to all electric. It's different and more convenient, but I do miss my old WFO at times. Still makes great pizza though, and most folks won't be able to tell the difference.
One of the reasons it's slow is because CG bitmap contexts are pre-multiplied, but the Canvas spec requires things to be not-premultiplied, so there's a bit of extra math that needs to happen w/ Canvas vs. straight CG/Quartz.
> (1) The PNG contains an embedded ICC color profile* (likely Display-P3 or another wide-gamut color space),
Why didn't you check? From what I can tell when I did, there is no color profile in the original image so it'll default to sRGB. This really looks like a gamma issue of some sort (see @perching_aix's comment).