Your problem may be more complicated than you think. I have read where Smith has changed the innards of their guns to be "California compliant" which means if you drop the gun with the hammer cocked back in single action mode it will not go off. If this was the case with your gun a simple spring change may not do much to lighten the trigger and would do nothing to smooth it out either. If you can find a gunsmith to work on the trigger and change it the warranty will be void and you could end up in court if you dropped it and it went off because of a non-factory trigger job that modified it from its safe factory configuration. A smart lawyer would bankrupt you without even pausing to burp or fart.
If you can live with the single action pull I would do nothing to it and as far as the double action pull I would never use this in a real gunfight because you stand much more of a chance of missing and killing an innocent bystander if a precision shot is mandatory but on the other hand if the fight is like most fights you will be so close (arms length) even if the double action pull was way over 13lbs you probably would not miss anyway.
I personally have gotten so used to using a single action pull that when using a revolver or an auto I just thumb cock on the draw and the pistol is cocked before it even comes up to eye level. I find double action shooting completely useless and unnecessary for me personally and would not trust myself to use it in a panic situation either unless the fight was only at arms length or across the barroom table.
If both hands are free you can get a death grip on the handgun and cock it with the non-shooting hand as it comes up to eye level and if you are only able to use just one hand because of an injury thumbcocking on the draw is not as complex as one might think if you practice just a short time doing it and of course without any live ammo in the gun.
Your cheapest way out would just be to try and adjust the mainspring and be satisfied with the small decrease in trigger poundage. This way you did not alter the factory trigger pull and no lawyer could attack you for having a non-standard and dangerous altered trigger that could end up injuring or killing not only a bystander but you yourself as well.
Always remember to live in the "real world" not the fantasy world of the internet.
Your point and caution is well taken.
However, I think you over estimate the lawyer world and the risk involved. Winning the lottery is not something rational to spend time thinking about, it is so rare. Wrongful or negligent shootings are about that rare.
A lawyer involved in a shooting event is either a criminal case or some negligent shooting event. We do need to worry about prosecutors in the anti-gun states and cities, that is a real risk. Self defense is discouraged, especially with a gun.
The trigger pull issue is a very long way down the list of reasons to find "proximate cause" or solid reason to claim someone was injured because of that issue.
The only way that might occur is with the "too light" trigger pull. We hear that often with the Glocks and the 3.5 pound trigger instead of the 5.5 factory trigger. But in reality, it only comes up when the shooter claims the gun accidentally fired, or fired before they wanted it too because of the "hair trigger".
I have a 12 ounce trigger on a Peacemaker, I love it. I also know competitors that have 1 pound and 1.5 pound triggers on Glocks used in competition, they are wonderful. But we recommend against these very light ones because they "go off" too easy when moving around or maybe being emotionally out of control in a confrontation. Those guns used in a negligent or unintentional shooting would give the lawyer that opening to go after the big bucks you mentioned. But anything factory level is simply not likely. They have to go after you, as the shooter, not the gun.
You can make a case that any gun with a Wolff Spring kit in it is inherently dangerous, I grant you that. However. I am not aware of any case ever where that trigger weight was the cause of some big jury verdict. There are just too many other factors to get past.
Think about it. There has to be someone shot, that should not have been shot, which means the shooter was pointing a gun at or toward the victim. If there was a lawful reason to do that, then the case turns on whether the shooter was logical and reasonable or maybe there was an over penetration issue. An time you point a gun and launch a bullet you own it for a very long time. That makes a very good case for things like frangible ammo or perhaps the 410 pistols for defense, shuts down the threat, but not things a half block away.
So, from the lawyer standpoint, I came from 4 different law enforcement and military backgrounds using guns every day, then law school put me in the courtroom, unarmed, most of the time, I did carry armed as a prosecutor when under threat. From that perspective and spending my last 25 years or so of my work life, in courtrooms every day, I just have not seen any wrongful discharge cases. They are more common among cops, shooting too much and bullets going astray.
Plaintiff's lawyers are the group of lawyers given that name because they chase ambulances and work all of the personal injury cases. Usually trying to form class action cases against some product. The reason is only one case can make you a millionaire, sometimes many times over. In the plaintiff's lawyer groups, they are organizations and they publish the latest methods of "get rich quick" methods of creating these cases. Notice I said creating. They twist the facts a bit when they get before the jury. These organization publish these methods and trends. There is nothing out there in the lawyer world promoting light triggers as a method to launch some new cases and get rich quick. There is just not enough of those cases, to promote an interest.
My point is, I do not worry about a light trigger or even a Wolff Spring kit in a gun. No question, if you shoot someone accidentally and have a spring kit in your gun, that would be an issue. But it is so rare, I say just forget about the lawyers, so long as you can safely operate your gun.
Not to worry. And by the way, from my cop days in the 70s, I too cock my wheel guns on the draw. I have done so when bad guys had guns and the cocked model 65 in the face is what prevented someone from dying that night. It is the same as drawing my cowboy guns, gives me a precision shot the first round. Now carrying other guns it is not so common, but as you said, it works. And in self defense cases you normally only have one hand on the gun, accuracy is much better with the cocked gun that a double action pull of any type. I also think that is why people carry stricker fired guns, much easier to shoot with one hand.
FWIW