Someone with a better background in this area will surely chime in. I have three sources that have directed my way of thinking, and all of my defensive carry weapons are now OE. In Alaska, where I live, there is a "stand your ground" law, so citizens here are not required to do their best to leave or run from an attack, breakin etc. When it comes to civil court, things such as trigger pull are big areas of concern (especially in accidental shootings). Lighten one up and your opposition can make some hay. One of my sources was my son's father inlaw, who was a US magistrate and a very strong advocate of citizen carry. (His court was in upstate NY) We talked about what would and wouldn't look good to a jury. Ammo had as much to do with being able to convince a jury that you were at least partly at fault. Hangover from the "black talon" days. His advice was to stay away from military rounds, and stay away from anything named or made primarily for law enforcement. It seems that the anti's have done a good job of convincing a great deal of the non gun owning public that fmj is for piercing armor and that anything designed for law enforcement really should not be in the hands of civilians. Kind of scary, and it probably depends on where you live. He did say that things that were dubbed "defense" and "home defense" rounds were things that the antis had more trouble gaining traction against.
Your question about the custom is a good one. A retired police chief advised me against carrying any of mine. Again, it probably wouldn't affect the outcome of someone attacking me in my home, but say I got into a parking lot altercation that escalated to me pulling one of those out and it could be made to look like I was "spoiling" for a fight if there was anything else suspicious. Three sources, a man who sat the bench, one who defended people, and one who arrested people all agreed on was that in some cases, it depends on what a DA may have as far as future aspirations, when it comes to them building or considering a case against someone like me.
Reloaders are always starting from the penalty line it seems when it comes to juries. So I don't carry my own recipes anymore. If I really felt like I would be better off substantially by carrying a round that is specifically law enforcement oriented (but legally available to citizens), I would still do so, but again, that is the case where the three point rule (1 Shut up. 2 Shutup. 3 Shut up.) rule would definitely apply.
The most important thing in his estimation (the judge) for anyone who is going to be questioned about any shooting (applies elsewhere too) is to do nothing more than calmly identify yourself and state that you will answer questions as soon as you have advice from counsel, and DO NOT waiver on that. Worry less about how that will look, and more about what you are likely to say and how it will be made to look. Very hard, but sitting in any cell waiting for your counsel is a more optimistic situation than waiting your release.