Losing a trial because of reloading rounds for self defense is way overblown as is at the bottom of the priority list. Training, attitude, discipline, and knowledge are at the top. I'm sure the person in this case was lacking in those areas.
I would discourage reloads for other reasons such as reliability.
The "home rolled" SD rounds and firearm modifications thing comes up all the time.
I discussed this with one of my best friends many times. He's a former prosecutor and also somewhat gun enthusiast. I've also discussed this with his attorney friends, many who still work on that side of the system. They all agree that if the element is legal, it
should not have any bearing. Yes, a prosecutor could try to use that to sway the jury, but they all mentioned that a good defense attorney should be able to handle that. The main point was that it comes down to if the use of deadly force is justified.
Again, that's not to say that such things could not be used against you in the court of law, or in a civil suit, etc. Just that it seems like this is another one of those cases where perpetuation of myth over reality.
Personally, I don't alter the triggers on any gun that I might use for defense. However, that's more not wanting to go down that rabbit's hole of seemingly endless mods to my firearms than anything else.