Boring a 7/64" diameter hole, hogging out the vacuum port (q.v., 22-cent mod) may improve throttle response. Yet . . . CV carbs by nature have an inevitable delay in throttle response. Our Harley brethren compensate to some extent with an accelerator pump on their CV40 (NOT CVK40) carbs.
Installing a slide carburetor with an acceleration pump definitely will improve throttle response.
Plain ol' slide carb (without accelerator pump)? Better throttle response, but . . . some unwanted consequences, in some situations.