Sure it's faster, but is it as safe as zex?

Also, how is the NX kit engaged? I know zex is armed, and then it's activated at WOT.

I'm looking for the optimum in safety when using this. I plan on having an a-pillar pod cluster with an A/F gauge and an EGT guage just to keep things in check. Anything else I need to do to ensure safety (besides strengthening engine interals, which is obvious, but I already said I don't want to mess with my engine)