Since 1998 have had very long life from Magnecor ignition wires on a 1995 Magnum 5.9 V8, although I am using their highly RFI suppressed type wires.

I did ruin one wire about 10 years ago but it was my fault.

When I read in
Willem Weertman’s book Chrysler Engines
that the metal shield are there on Magnum style engines
simply to let Chrysler buy lesser quality rubber for the boots,
I used curved jaw channel locks to squeeze and remove them.
Using the higher quality silicone of the Magnecores is in my opinion way better than having metal shields that can clog from splashing soupy mud.

I used to test wires by submerging them in salt water and using a Bidle Megger.

After getting a tip here on Moparts I now wrap the wire with aluminum foil and Meg from foil to center conductor.

I have tried over a dozen sparkplug designs and feel that NGK Iridium alloy tipped plugs perform and last best.
In trying all those plug designs I have pulled boots off a lot, but with the Magnecores have not ruined the connector.

I use dielectric grease and twist the boot clockwise, then counterclockwise before pulling off.
Once the metal shields are gone, a Lisle tool type sparkplug plier can be used.

Thanks for the input.

Does the foil act as an insulator?