There is nothing to update. The house passed the Uber bill in March, the Senate did not vote on it before the session ended in late May and they went home. They'll have to start over from scratch when they convene next January, and even if they pass something next spring, it won't take effect until next August, 2017, so we will continue to dodge that gold Impala for another year...at least.
Here is the map that shows where your UberX driver's app will work, excluding the airport:
(I don't drive Uber Black, but from what I understand, if you do, the app will work at the A/P, but not in St Charles county.)
Two tiny glitches make it a bit easier to PU in both. People CAN drop a pin at the MetroLink Station at the A/P and on a sand bar on the west side of the MO river just north of I-70, which comes up as 1 Ameristar Blvd, then call you to tell you where they really are, if they are somewhere else at the A/P or in St Charles County. Alternatively, they can drop that pin ANYwhere else and make the same phone call. I have had no problem starting trips in St Charles county, no matter where I pick them up.
On the Rider's app, I see Uber X cars staged in St Charles waiting for pings. One is usually in Time Center apts, one a bit farther down 94, one up on the north side, near New Town, plus a few others less consistently. I assume they wait at home for pings, and I assume they get them, as I see them disappear more frequently than just logging off would indicate.