If anything, the power should be more controllable with the 6 speed since you are choosing the gear. Performance will be slightly less since boost will drop while you shift (more slowly than the DCT shifts). The 6MT is likely stronger than the more complex DCT. Torque is still pretty low, so the clutch should be fine (clutches are rated by torque not rwhp). Even an ESS VT650 with all the bolt on mods is struggling to break 400 lbs rwtq.
Go for it. I have never had too much power. With a centrifugal supercharger, the boost comes only with rpm and with a high revving low torque engine like the S65, power comes in slowly and predictably. Centrifugal supercharged power is very controllable. You won't have any issues.