This sounds to me like an example of 'Optimization during the Design Phase'. You might consider a quote from Brian Kernighan -- "First make it run. Then make it run fast."

The Agile Process folks have a saying -- YAGNI. Don't spend time in the design phase on anything except solving the current problem at hand. All too often any optimization during your design phase will turn into examples of the 'You Ain't Gonna Need It" principal in action....