Hey,
There are not any "extras" calculated for pre-order. We do order some more for testing and for replacements. Best way to get one now is to wait and see if someone bails on their order, or until next batch order next year.
Taylor
Looking forward to the second batch next year (Any idea what timeframe? Q1, Q2?). The slate case ticks so many boxes. Congrats on shipping this first batch, as well!