That's because I think "Why would you waste time practicing these techniques? I need to be ready." My thinking definitely crosses into hypervigilance territory. If I'm to think "Hey these techniques can help me!", I'll immediately counter it with "Why would you want to be free to take your time? If you take your time, chaos will ensue."
That is some quite inaccurate thinking around readiness and relaxing, right there.
Mindfulness practiced correctly *means* your mind & body are balanced, at ease, calm *and* ready - and able to realistically assess & tackle the situation in front of you.
Mind you, coming from someone who doesn't even *like* DBT take on mindfulness, just the state itself, techniques to reach it via martial arts or sport, and just appreciating everyday beauty.