The N frame revolvers are strong, relatively compact, and light weight (compared to the competition.) You can actually carry most of them in a belt holster all day!
However, when you mount a scope or red dot sight, you must remove the factory installed rear sight. This makes it difficult to switch conveniently from scope to iron sight use (and vice versa) while in the field. The N frames (and perhaps some L frames) need a built in scope mounting base which allows the shooter to leave the rear (iron) sight in place when mounting a scope. With such a design, the shooter could quickly switch to iron sight use by simply removing the scope. S&W has some PC hunter models with integral bases which might serve as a starting point when designing such a frame.
Such a design could be implemented by simply milling the scope base into the barrel rib (like the Ruger RH), but this approach puts too much weight forward to balance properly. So I think a frame mounted solution would be better.
I'm aware that Warne offers a scope base which includes an integral front & rear sight for emergency use. But the included integral sights result in a short sight radius.
Another approach would be to mill a Pic. rail or Weaver style base into the frame without the traditional adj. rear sight. Then design an adj. rear (iron) sight which can be mounted directly onto the integral base and easily removed as well. This solution might require too high of a front sight, however.
A third solution would be to have the integral scope base with no provision for a rear iron sight. This solution would require the use of a compact reflex dot sight (like the Burris Fast Fire) as a substitute for iron sights when a fast, accurate, lightweight sight is desired. Some of the compact reflex sights have been improved to the point that they are rugged and reliable enough for hunters, target shooter, and sportsmen to use. This, in my view, is the best solution (albeit the most expensive.) The shooter could use either the reflex sight, a full size dot sight, or a scope and would have the capability to change from one sight to another in the field. I realize that the shooter can do this with the current N frame by simply mounting a Weaver base, but that increases the overall height of the reflex sight or scope a little too much. It also makes the use of the compact reflex sight a little too bulky to adapt to use in reasonable sized belt holsters.
Creation of an improved N frame for scope mounting would also provide a good opportunity to improve other features of the N frame (like lengthening the frame and cylinder a tiny bit to allow for the use of longer bullets).
The integral scope base would not be needed on all models, but the models with barrel lengths greater than 4" inches could benefit from integral bases.
I know this suggestion might not be as fun and exciting as a 10mm M&P with integral phaser, but I think it's worth doing.