We are looking into publishing a legacy AIR app as a captive runtime build on the Mac App Store. Adobe's outdated documentation describes the steps involved, but in some places references tools/workflow that are no longer applicable.
The thing I'm most hung up on is the application icons. As noted in that article, when you package for Mac captive runtime, the AIR SDK compiles the icons into an Icon.icns file. The icon file is supposed to have a 512x512 icon but the SDK doesn't support it 🙄, so the developer must manually edit the ICNS file to add the 512x512 icon.
Apple deprecated support for the ICNS format years ago and no longer ships the utility that could be used to edit this file format. These days, icons are supposed to be bundled as part of the Asset Catalog, but I don't know of any way to make an Asset Catalog work with a Mac build (unless the Assets.car file for iOS will also work on Mac?).
Is there any way to add the 512x512 icon these days? Has Harman added support for this icon size, or added support for Asset Catalogs in Mac builds?