I can't believe that on flight following that atc would let FLIPS go over their air space at 10,500.
i have done it on a number of occasions. I listen to them holding the ORD departures at 10,000 until they pass me (except for one they missed and the guy started descending to to a TCAS RA).
One of my trips was like this, I'm heading towards Chicago land at 10,000.
27K: Is there any altitude I can get that won't involve me having to go to KELSI?
C90: Let me check...<pause of about a minute>... no.
27K: OK, here's what I'm going to do. Cancel IFR, climb up 500' and you're going to give me flight following.
C90: That will work.
Now pretty much I file to GYY and just cancel and make the decision whether I want to climb to 10,500 or go down to 2000. I've never had had any problem getting following through the area however and they've never suggested anything other than calling out traffic.
Last month, I am blasting along at 12,500 and when I got my handoff to C90 it went like this:
27K: Be advised, at GYY I'm going to turn direct OSH rather.
C90: Yuck...I suppose you won't be descending from 12,500 any time soon.
27K: Negative
that was pretty much how it went (complete with the Yuck).
As I said, MKE is a different story.