I don't have a specific timeframe, but I would expect to see them this coming week.
As aluminum plates get larger, the curl on the material becomes more apparent. It's important to remember that aluminum sheet is extruded, then rolled onto a huge spool. It is then rolled off this spool and cut into sheets. If you have a large piece cut from the outside of the spool, the curl is less noticeable, but as you get to the inside, the curl is a little more pronounced.
Ultimately, mounting the power transformers tightly should help align things a bit, as would the weight you are applying.
-PB