An interesting discussion on /r/Wordpress – 10 Steps To Faster Wordpress which, more specifically spawned a debate over the opportunity of disabling / slowing down Heartbeat and using hosting cron vs wp_cron, see subthread here.
I have used https://wordpress.org/plugins/heartbeat-control/ for friends using super cheap shared hosting to get improved speed improvements, it hasn’t been updated in years but as far as I know it still works.
Heartbeat is a nightmare for performance. I’m running a dedicated server for an university. I use the Falcon plugin to disable Heartbeat (it does more than that). Everything is fine until I disable it. The editors often see 500 error and CPU is often at 80%-90%.
its pretty interesting discussion but ill take the side of disabling it or spacing heartbeat out. i also use heartbeat control. the attitude though. people needs some weed on that discussion thread