Why do you say that? It takes away from the system's simplicity?
Perhaps it should be an addendum to their Preferred system. Obviously, a bad run is no statistical analysis, but if there is a correlation between the count and a bad pull on an 11, it should be addressed.
What are you going to do, not double 11 vs. 6 because there are a lot of aces left?
If the numbers support not doubling down, I won't double down. Is it any different than sticking on a 16 vs. a dealer 10 if the count says that's what to do? I just wonder if anyone has looked at it or any existing systems deal with it?