Think I found an obscure shipyard issue.  Past a certain distance, sponsor planets give a minimum 1 Manufacturing point.  In Govern under Adjust Production Spending I set Military Manufacturing to 0%, then hit Reset all planets to use global spending.  This properly set all sponsors for the shipyard to 0 Mfg - *except* for the distant planets which remained at 1 point. 

Not exactly a massive exploit; but even distant planets should probably only give 1 Mfg as sponsors especially if the close-by sponsors give 0.

- jeff