Handcuffs, I use them at work.
If I'm not at work I will be distancing myself from the adversary and seeking cover. If the felon wants to run away from me, great. If he complies with my orders to "prone out" great. I'm still not touching him with a 10' pole. In short, I don't want to be anywhere close to my adversary. Handcuffs, to apply them, force you to come in to contact with your adversary.
If he or she is injured in the encounter, not good, great or bad, they are just injured. No, I'm not tending to an adversaries wounds at that time either. It could just be a trap to "lull" me in. Like I said, I want distance.
Unless you are a LEO that is required to carry them off duty I see no need for them in an off duty, or non LEO application. That's just my $0.02. If this has already been stated, I apologise. I didn't read four pages of post just to give my $0.02.