First thing to know!!
Full cure on spi epoxy is about 90 days, and for a good reason, as all, I care about is durability; adhesion comes with any product as it cures.
Next, dont compare my product to an industrial product.
If you had called, I would have told you not to use my product the way you did and would not have sold you any.
You want to test it let set 3 months and see if you can blast off a door without destroying the door, then soak for months in dot 3 brake fluid.
As nice as I can above, I will add one more thing you don't understand zinc, temp, or acids.
I feel like talking to a wall, so I left out many answers to what you posted, but I think this will help you understand your issue.
A few years ago, a shop said he had used 100% of a major's paint line for, I think it was 13 to 16 years, and he did a car following the perfect paint job with his paint company's products.
The epoxy failed six months later and threatened to sue me, all
I said is hope you do!
The paint line is a great line, but the epoxy is made for insurance work and speed. Not long term life.