TFL policy; not firearms related...
The non-lethal or less-than-lethal topics/remarks are not considered "firearms related".
But to answer the member's question(s), I'd suggest having a non-lethal weapon to support/augment a firearm. Impact weapons, tactical pens, OC sprays, and Taser systems can help avoid a lethal force incident BUT remember that you(the armed license holder) are NOT a sworn LE officer or special agent.
Tasers(the C2 model) are very good, IMO for general use.
Many unstable or intoxicated subjects do not comply with most OC sprays-agents but there are a few brands worth using(Sabre Red, Vextor, First Defense).
Massad Ayoob, the author & legal use-of-force expert wrote about Mako Group's new polymer impact weapon. It is lightweight(9.1oz) and has a glass breaker function built into the design.
That could be handy in a emergency.
In closing, if you choose to buy any non-lethal devices, get documented skill training(that may help in court) and know the local laws re; use of force.