Collecting performance data

How does one go about collection performance metrics from game builds? I'd like to get a general feel of how my game performs on some hardware that's not my development machines, but cannot seem to figure out how to go about it. I can enable the profiler in a development build via Profiler.enableBinaryLog/etc., and the build can spit out a profiler log, but I can't import it back into the editor profiler to view it. Or rather, I can, but only about a thousand frames (out of over a million), which is completely worthless. I can't slice the file up to import smaller sections manually either, since modifications break the profiler signature. The Analytics feature could maybe be co-opted into performance reporting, but in general doesn't seem well suited to this task at all and from what little I've read on the Unity Performance Reporting feature so far, it doesn't actually sound like it reports performance and seems more like an error monitoring tool. I can't seem to enable it to find out, either; when I try it just tells me I must have a paid subscription (which I do).

Am I missing something here or just plain stupid? How do you other folks go about doing this sort of testing/metrics gathering? Do I need to write the entire thing myself?