When I did the Columbus Loophole last Summer where the Empire Builder Sleeper portion ends just north of Milwaukee and a regular Coach ticket takes over, Stephanie the SCA told me to remain right where I was without me even having to inquire. She lifted my Coach ticket and took it up to the Conductor to save me having to chase him down. I'm certain she is familiar with the Loophole and I understand from other posters who have taken this route this is common practice, especially considering it is highly unlikely anyone would book Sleeper from there on into Chicago.
Could you please elaborate on that loophole, as I was looking at the zone map and the way I read it MKE and CHI are in the same zone.
That (and other) loophole is closed!
It was from Kirkwood, MO or Kansas City (and other Cities) in the Central zone to Columbus, WI (CBS) (also in the Central zone - for a 1 zone award! However because you would have had to stay overnight (on your dime) in either St Louis or Chicago, Amtrak routed you via KC, LA and Portland to CBS (which are all same day connections) - all for a 1 zone award!
Then you would just have to buy a coach ticket from CBS to Chicago!