After you look at the legality of this and provide a waiver for submitted videos a leader board on a couple categories would be great. In the military there are several areas we compete within each unit and then across units then eschelons above.
So, with that tidbit of a vision, start off identifying the categories; speed, materials cut, accuracy, depth, etc. Then begin the entry system.
Following the prototype/crawl phase of submissions, then it’s time to throw the gauntlet toward a competitor or a benchmark forum, maybe in a forum that is not under a specific machine but more a maker’s generic forum to get the competition sizzling! An xCarve, avidCNC, or a vCarve acolyte will pop up and take up the challenge.