LOL! Whether or not you were trying to make a joke, that is such a good point! The world's fastest man can't head back to his house, or a public restroom, for a few seconds?
Because it wouldn't be as cool??
He can't do that while in another country. Or outer space! haha..
He's clearly just too important! Didn't you know? *eyeroll*
Surely he's fast enough to fight crime naked without anyone noticing, thus negating the point of getting changed in the first place?(or in business attire, or whatever he wears when he isn't pulling costumes out of his ring)
This is a mote question because his costume is now made of speed force energy which any speedster worth their salt should be able to control.
Soylent Dave, you're right!