If I use a CoPoly, it'll probably be as a cross. I realize this is not as advantageous as having the CoPoly in the mains. I've read a bit about changing out CoPoly before they die. Does this also apply to strings in the crosses? Because of my work, I may have to leave a racquet strung w/ copoly crosses in the closet for a week or two. When playing it seems like the strings do snap a bit earlier (around 8hrs) which is fine for me as I usually cut them out at 10-12hrs.