Making it easier to have an RGB file for printing to a large format inkjet?
(only saying inkjet made me think of a consumer product).

Current option for creating a document is for presswork --
Have to change the transparency blend space to RGB to take advantage of the larger color space available with the extra inks there.

MAYBE
The top bar that is above the document frame (has the home button in the corner) Can that be a different color to indicate if you are in a CMYK or RGB blend space?

You already know the color issues if the correct profile is not chosen...
The visual could be in the preferences so those that do not work in both color spaces and do not like a different color can turn it off.