It also was not just the mesh as Rob mentioned. I had a Pioneer with two panels on one gore next to one larger piece of mesh. So two pieces of white fabric next to one piece of mesh. Had seen identical conditions since sewn together. One panel full strength, one completely degraded. The two panels might have come from different lots, batches, rolls etc. but had been sewn next to each other. We gave Invista, maker of nylon filament, samples of bad fabric. IF they discovered the issue they never told the industry. I did several high tech spectroscopic analysis on the bad versus good nylon. I couldn't identify the difference.
To the OP, I pack a lot of old stuff but I would not pack an old Securty LoPo in a pilot rig.