[HO455]

Following up with this. BigBird05 was kind enough to send me a factory switch to disassemble and compare.
There is a difference in the design of the contacts and how they are operated. But there were some differences I noticed between the two that may lead to the contact failures
New aftermarket switch contacts are cone shaped compared to the factory's dome shape. Which seems to me the factory contacts definitely have more surface area conducting current. In addtion the higher amperage factory contacts are copper. (The 2nd photo doesn't show the difference contact materials very well.)
The other difference that was noticeable is the springs behind the contacts on the factory switch are at least 30 percent stronger.
In the 1st photo the arrow indicates the contact for the solenoid. The contact has a wider wear pattern with little indication of arcing. From the metal shavings it appears this switch failed mechanically not electrically.
In the 2nd photo notice the amount of arcing. It's easy to believe that would be enough to cause the wiring to overheat. The smaller contact area has some got to be a contributing factor. I also believe that stronger springs would help the contacts to clean themselves of arc damage when they pass over each other.
All comments are welcomed.

Thanks to BigBird05 for the switch!