Excellent!  I pay price for not reading all of thread.  I will review now.

EDIT: After review, if take 5000 eligible units and increase throughput from 210 to 255 mhash/sec, will generate almost 74btc extra per day at current difficulty.  If take all extra, exceed 700btc in less than ten days.  With real commission, inverse ratio for break-even.  19 days for 50%, 38 days for 25%, and so on.

5000 units is 1250 4-chip boards.  That is acceptable estimate.