Acrobat's Output Preview works the same way-- you can turn off the black plate. Are you trying to hide the black plate or create a file with no black values? It should be possible to make a CMYK profile with no black generation, which would convert RGB to CMYK with a blank black plate.
I'd like to create a file with no black values. One that could be flattened that way. Is that possible?
A CMYK profile could have no black generation. You can make one with Photoshop's legacy CMYK setup. Not sure why you would want to do it, but any conversion from RGB or another CMYK profile to the no black profile would produce a blank black channel.
From Photoshop's Color Settings choose CMYK>Custom. Set Black Generation to None. choose CMYK >Save and save the profile to one of your profiles folders. The saved profile should then be available to both ID and Photoshop for making conversions.
Theses colors all use black
Forcing a conversion from default SWOP Coated to my custom No Black profile
The default black swatch converts to 88|81|74|0