FTR I'm at the point where other things being equal I'd prefer to put optimizations in 2.1.
FTR, I agree in general. But in this case, we have a rather simple to fix bottleneck that makes a non-really crazy use case be 20 times slower than what you would go with thrift. At this point, it's not really an optimization imo, it's a bug that needs to be fixed. But I do not mean this ticket to be "let's do every optimizations for BatchStatement on single partition that comes into mind", that would definitively belong to 2.1.