Tentatively confirming the font substitution bug appears to be fixed in Illustrator 2026 (30.0)

I've been using the latest version of Illustrator for a full day now on files that were completely wrecked by the font-substitution bug in any version from 29.5 onward. There have been no major issues, and I've been able to process files normally with no crashes. Hopefully, I'm not jinxing anything by saying that Illustrator seems to be back to normal, at least for the time being.