hopefulDownload this zip file of the raw output of the camera. Unpack the zip file (it will unpack into a bunch of directories) and apply any one-step method you can think of. Hint: FreeMXFConverter will not do it in one step. Adobe Premier Pro will, but costs a lot of money, and you can't actually buy it, only lease it.
I do appreciate the advice, really, and I know that people are trying to help. I speculate that the idea that a camera would produce separate files that are so difficult to join back together again is mystifying to most people. It surely wasn't something I expected to encounter. But the needs of professional production are different from how most consumer work happens, and the pros have access to the expensive software necessary to do the production when they need it, so it looks effortless.
Another warning about this test: The resulting file is less than 90 seconds long. The amount of time you spend converting and combining it may be misleading. When we get the opportunity to do so, we will shoot a 30-minute file and if possible make it available so anyone wanting to take a crack at it can see if they can make it go faster than I've been able to do so.