I work at Disneyland and the enforcement of their costume rules are hit-and-miss.
I see people in costume every day, ranging from the Bounders to people wearing near-complete outfits (Jedi robes, belt, and lightsabre but with ordinary shoes is common) to people wearing complete costumes head-to-toe.
I see guys in full Han Solo outfits including boots and holster all the time.
A few weeks ago I saw a Mandalorian wearing his helmet.
Last week I saw an Ahsoka Tano in full costume including full face makeup.
I'm in New Orleans Square, so the people I see have got in through the front gate and walked all the way from Main Street to where I am without being stopped. What I don't see are all the people who get stopped! I have no idea how many of those there are.