avoiding schrunching

[spennie]

Avery stickers? Buy a Sailworks, already has reinforcing film on that area!

[dllee]

The extra backing idea is a very good one.
I think DE-rigging is what causes the monfilm/trilam to fold, NOT rigging. When you stuff the mast up the sail, YOU control how much folding is involved, so don't crease your sail, roll it.
When you DE-rig, you cannot control that area above the boom, behind the mast, from scrunching loudly, thus creasing the material there.
Your sail lasts only as long as it's weakest area.
For some, it's the leech near the head.
For other's, it's the foot of the sail getting bent and delam'ed.
for other's still, it's the area above the boom, behind the mast.
And for other's, it's the clew, just in front of the tack.
Of course, some sails look new, but the head falls apart, where the strap at the top cap attaches. Then of course, the luff up top, where you stuff the mast thru the curve.

[isobars]

Which provides the best performance and reliability per buck ... replacing them often (yearly?) or running them into the ground?

Four variations: Pick a number and a letter.
1. Buy new every year at quiver discount prices.
2. Buy one-year-used every year so the first owner suffers the biggest depreciation.
A. Keep them one year then sell.
B. Run them 'til they die.

If you rig on grass, 1A might work for you. It surely buys you a clear view, top reliability, current technology, and great resale.
1B may be optimal if the first owner rigged on grass.
2A makes the first owner eat the biggest depreciation AND gives you solid reliability.
2B may give you the most days per buck, but costs you reliability, view, technology, and maybe a swim some day.