There was an earlier topic in the bugs about Photo AI failing if there was more than one alpha channel. It was dismissed with “get rid of the other alpha channels.”
That’s sometimes not how working in Photoshop goes. Some users are working with exact selections, and are working non-destructively. Consequently, they save selections, and sometimes create alpha channels for other reasons - like refining a selection. It is not uncommon to have a number of layers, selections, and alpha channels in an image that doesn’t go to Photo AI until AFTER it’s been through Photoshop because they DON’T want sharpening performed until all the processing is complete.
Yes, it is possible to run Photo AI from Photoshop, but when run that way the user cannot make use of the upscaling - and whatever other tools may be disabled when run within Photoshop.
And, since Photo AI won’t process PSD files, saving in that format as an alternative to TIFF isn’t available.
I consider this limitation on channels to be a bug that should be addressed.
