There is no such setting.
Did you try making two copies of the text, and reverse the background/type color on one copy? Then clip the top copy to show half of the text (with Edit > Paste Inside).
That wouldn't work as the project involves diagonal lines and large letters so they colour change would occur midway through letters.
No worries if it's not possible, i'll see if I can come up with a bodged solution.
Sorry, I mis-read your request. I thought you wanted the transition to change within words.
You can do it if you don't mind the text outputting as a 4-color black:
In the above example I've set my Transparency Blend Space to RGB. The text block background is 0|0|0 RGB black with the text as RGB white. On top of the text block to the right there is a frame filled with RGB white with its transparency Effect set to Difference.
This might be a problem for small text because with the RGB blend space the black will output as 4-color (the mix will depend on your document's CMYK profile)
Also, you can get black only output if the document CMYK profile has a maximum black generation, and that might work if there isn't critical color on the page or you are working in black and white. So here the document profile has a maximum black generation, followed by default SWOP and you can see the difference in Sep Preview output:
Good work around!