Would be nice to add an additional document color mode with CMYW or CMYKW
Would be nice to see a feature to include the color white in the document color mode as either CMYW or CMYKW as an addition. There are printers that use all 5 printer color inks. (Cyan, Magenta, Yellow, Black, and White)
Special printers that utilize white ink to print onto black (or dark-colored) t-shirts can be useful if white is included in the document color mode in Illustrator. This will play a huge role making white more vibrant from the printer.
Use White Spot color instead. Printshops have tools to parse it, separating all 5 colors just perfectly.
Because you just have no idea what your CMYKW as a mode will break :/