Speaking as a sewer, I know how hard it is to align plaids so I'm not surprised that they do bias chest pockets so much in RTW. The placement is less tricky and you can use off cut scraps for it. I don't mind bias chest pockets as long as it's not a large irregular plaid (not symmetrical in both directions).
On the whole bust flattery thing, I used to avoid bust pockets like the plague, because I thought it would draw attention to my bust. Then I realized that I'm also really a pear with narrow shoulders, and the pockets did a good job of drawing the eye up visually in general, so I became ok with it. I still avoid flap pockets or anything bulky Ike a besom pocket, though.