What could go wrong?
There is a great value in knowing that a plate full of samples is going to have a perfect standard curve every time right out of the box. Similarly, a prespiked plate to which purified water is simply added to reconstitute the standard curve and samples are added on top of predried spikes is a time saver and a tedious time at that (adding 10 microliter spikes can add ambiguity: "...did I spike that last row, I can't see it").
The old maxim that "the most expensive test is the test that must be repeated" is a good one.
Even a non-product failure involves an investigation checklist (at least) and thus a time-encompassing exercise prior to performing a repeat test. This can be avoided with a pre-spiked plate.
Consider also that the EZ II Go plate doesn't even contain a standard vial to be reconstituted. NOT opening a CSE vial, NOT mixing a CSE vial, NOT diluting a stock CSE, and NOT plating dilutions of CSE will avoid perhaps the major reason for false positive tests in that the random ejecta of CSE droplets cannot land on your plate during test preparation. Because its not there.
https://www.biomerieux-usa.com/product/endotoxin-detection-assays-services