Add further notes on our findings on preformance issues.

4 jobs from parallel_for in 3 minutes 32 seconds (queued for 1 second)
Status Job ID Name Coverage
  Build
passed #2880
build_cmake

00:42

 
  Test
passed #2881
run_tests

00:39

 
  Sanitizer
passed #2883
run_address_sanitizer

01:15

passed #2882
run_thread_sanitizer

00:54