Here is an update for Pittsburgh. At the main checkpoint, the leftmost lane is WTMD only. All other lanes are both WTMD and BKSX, one set per two lanes. On the far right is an express security lane, open to anyone with a single bag only. Next to it is the traditional elite priority lane. They both lead to the same set of WTMD/BKSX.
In summary:
PIT
Main Checkpoint - Left lane WTMD only; all other lanes have one set of WTMD and BKSX per two lanes. Express (one bag only) lane and elite traveler lane lead to the same set of WTMD/BKSX, with express leading directly to BKSX
Also, at ATL Atlanta, the first post of this thread says:
Center Checkpoint Lanes 1-4, 13-16, & 21-24 have MMW installed
On the right side (lower numbers), I saw an MMW at lane 4 and lane 12 only. SDOO is easy, as long as they have many lanes open. Note: They had two entrances to this one checkpoint. Seems like the right side gives the best odds.