Tekmos

As a practical matter, no. 

First, no one knows that it is your design.  The chip marking identifies it as a specific merge, but not which designs are merged on it.  It is extremely unlikely that a competitor would buy an ASIC from us in the hope that we might put a competitor's design on it.

Second, the design would have to be reverse engineered from micro-photographs.  While this is possible, it is an extremely expensive process, involving  man-years of effort.  Again, it is extremely unlikely that anyone would go to the expense of doing this based on the speculation that one of the designs might be the desired one.

Because of the costs involved, anyone with a serious interest in copying a chip would start by acquiring a finished system containing the correct chips.  And in that case, CAP security is enhanced because the additional designs in the merged chip increase the amount of reverse engineering that has to be performed.