As both Rastoff and I have both requested an actual clean shooting case where weapon modifications bore real, not imagined or speculative, legal bearing on the actual outcome I have yet to see one single case presented. I wonder why? Because despite virtual, forum discussion, speculation and hypothetical this has never happened in the real world. Take this from a lawyer who has practiced for years in Washington, DC, which is ground zero for rediculous gun charges and prosecutions.
If you have a valid claim of self defense, the efficiency of your weapon is irrelevant weather you use a blaster or a light saber.
That was kind of my point. The modifications used had no real, factual bearing on the outcome of the Alvarez case, but they had to be addressed at trial nonetheless, totaling a not inconsiderable sum (even in 1980's dollars). Unless you represent your clients pro bono, money matters. It does to me at least. A lot!
And I'm no lawyer, but, light sabers aside, I think it might be relevant in a court of law if you shot your attacker once with a 9mm or struck him 23 times with a 9 iron. Even if the end result were the same in both cases: you escaped harm, and your attacker died, I imagine that the efficiency of the weapon used would be very relevant indeed.