I did a little research on this, but the only thing I found was information about the Mozilla crash reporter which was apparently enabled by using --enable-crashreporter. That seems to generate crash reports that are designed for auto-submission, but presumably they could also be intercepted and sent manually. That option isn't used in any .mozconfig I've seen for a UXP application, and enabling it doesn't seem to do much.
The thing is, I've never actually needed a proper crash log or worried about things like this in the entire time I've been working with UXP applications... at most an application would generate some kind of core dump containing a stack trace upon crashing that I could look over, but I've never had to actually rely on the application itself to actually generate a clearly-labeled report internally that a user can submit to me explaining what happened during a crash.
If there is such a functionality, I'm wondering what I would need do to enable it. And if not, I'm curious what is done instead. A user just describing their problem without any solid information about the crash in the form of a stack trace doesn't really seem like it would help me resolve their issue.
I know this is kind of a rookie question, given that this seems like something I should know given how long I've been working with the platform... but I just have not dealt with the gathering info from users part enough to know how this works.