[MontagFTB]

Looping through inflate/deflate on rotated pixels still takes more time than updating a bit in the Exif (and the chunk’s associated CRC)

[crazygringo]

It's still negligible from the consumer standpoint.

Like, if you had millions of images you needed to rotate on a server in a batch job, then OK.

But if you're just rotating one photo, or even a hundred, that you've just taken, it's plenty fast enough.