Export image files (.png or .jpeg for example) in color modes other than the current. Is it possible?

For example:
1. Working in CMYK, I trying to export .png or .jpeg and get an error (of course, CMYK is not supported by this file formats).
2. Usually I work in 16-bit mode, so when I export .png, it's saved also in 16 bit and later I have to convert it in 8 bit mode by hand.

Hm... Not directly. Currently, you need to convert the image color mode and then export (and then you could do undo to go back to the original color mode).

Got it. Thank you for your reply.