I believe some AME's have done stints as copy editors. 4 to 6 years. Atex, and Macs for design. Only interns would qualify as tryouts, and then, not very often. Targeted training has been sparse, but talk of training has been increasing.
Extra pages are okay.
Copy editors can no longer sit back and be low-profile. Design and heads offer chances to shine. Do great work, make sure you get the credit and cultivate your own style and persona. This goes against our natural self-righteousness but we must learn to market ourselves. It's a business, after all.