When you start your presentation, there are a number of things to be concerned about: sound, lighting, props, material, stories, you get the idea.
Don’t let your body armor slow you down. Make sure you have items that are clean, pressed, and, more importantly, items you feel comfortable wearing in front of a thousand people (whether you are speaking before one thousand people or not).
Ensure you have more than one Costume: presenting in new or second-hand armor may not be comfortable to you, causing you to focus on your armor, not your audience.
Practice in your armor.