Add further notes on CPI performance.

4 jobs from parallel_for in 3 minutes 53 seconds (queued for 3 seconds)
Status Job ID Name Coverage
  Build
passed #3063
build_cmake

00:47

 
  Test
passed #3064
run_tests

00:44

 
  Sanitizer
passed #3066
run_address_sanitizer

01:23

passed #3065
run_thread_sanitizer

00:57