Thank you! Yeah, the bit of shirt coming out under a vest drives me nuts too, so it was avoided at all costs.
I did find a solution for the tuxedo shirt, too. I had some elastic in my sewing kit, so I sewed two bands at the bottom, which start at the back of the shirt and can be buttoned onto the front. They both end up sitting at the top of my thighs, so they don't give me a camel-toe. lol And yeah, they hold the shirt down on both sides!