Can macOS 10.13 High Sierra write HEIF/HEIC image files?

Apple has told us how exciting and efficient the new HEIF image compression is in iOS 11 and macOS High Sierra. So today I went to my High Sierra system, and tried to compress one of my 16 MB Camera RAW files to the new format, also known as HEIC.

Imagine my surprise when I was unable to find any app which was prepared to save an imported RAW file in HEIF/HEIC. Photos and Preview seem able to read them, but not write to them, except in Photo’s case as unchanged exports (it can’t export changed HEIF/HEIC, though). Third party apps like Affinity Photo, Pixelmator, and GraphicConverter won’t play either – with the latter informing me quite simply that writing HEIF/HEIC files is currently not possible in 10.13.

Thanks to @superpixel, who confirms that other apps such as Adobe Photoshop CC 2018 can’t write HEIF/HEIC either.

So is Apple going to eventually get round to providing write support for this wonderful new format, or is it going to be the first read-only image format supported on macOS? And how come iOS 11 cameras can write HEIF/HEIC images, but Macs aren’t important enough to Apple to merit such support?

I don’t recall Apple announcing this at WWDC back in June. Do you?