Quote Originally Posted by Highlander31 View Post
When I wore three piece suits, I had my tailor fit the vests and eliminate the adjustment straps. I did the same with the waistcoat for my pc.

Yes, and the seam allowances for the back panels of the waistcoat can be made fairly substantial, as well as darts added for any future expantion.

However, a lot of off-the-rack vests or waistcoats have knotches cut out of those seam allowances, so it doesn't follow that you can expect to do that for them too easily.