Debugging with MacOS Instruments

Has anyone ever tried to debug a host-app (or standalone processor) in the instruments app from MacOS?

I’m currently trying and I’m having a hard time to even isolate the audio thread. Moreover, I added a performance meter display (avg, peak and total milis for the AudioIODeviceCallback) to the UI but that value does not match the measured time profiler value in Instruments.

Does anyone have some experience they might share, on how to debug comfortable in Instruments?