No need for a manual controller on these cars. Subaru didnt spend all that research and development into their EBCS system for nothing, expecially on these newer models. The turbo dynamics system, stock for stock, will work to always achieve your target boost whether your doing WOT pulls on cold winter mornings or on hot summer dog days. You would have to make adjustments to the manaul for changes in seasonal weather (cold=boost spikes, hot = undershooting target boost)