In a previous life I managed to deliver a system with (basic-block) coverage measurement compiled in (gcov) but instead of the mess of files gcov generates, the whole coverage structure was streamed to a remote server (it compressed very well). Once that was in place it was an amazing telemetry tool.

Later on used Intel Processor Trace in a similar fashion for even finer (mc-dc) coverage.

Coverage tools are very useful, if a bit hard to use...