Load performance testing on real device - Appium iOS

Hi, I’m thinking to use Appium to record the loading time for our app on the real device.

But since apple did not fix the 1sec delay in instruments, so my execution time got from real device would not be accurate. I was thinking to minus the extra delay in my script…but still feel like it’s not accurate.

Anyone has better way to do load performance testing on iOS app?

Did you find a solution for this?