I suppose there would be one benefit from a zero profit share,...

I suppose there would be one benefit from a zero profit share, our company could be generous and offer to release DRR from its "loss making" agreement. In which case we could sell our manufacturing process to the opposition.

Of course DRR are making a nice profit, it is where that "profit" is made which is the key. My guess that the profit is in the manufacturing process, which we helped pay for, and which appears as a cost in formulae which determines profit share.