Explain in detail the reasons why Elementor/WordPress page editor lags: Heartbeat polling, auto-save and revision versions, plugin theme conflicts. Provide step-by-step troubleshooting and security optimization solutions without affecting the frontend experience.

Explain the most reasonable settings for WordPress Heartbeat Control: FM or disable by backend/editor/frontend zones, reduce admin-ajax.php load and CPU usage, and take care of autosave and edit lock.

In-depth analysis of the role of the WordPress Heartbeat API and optimization methods, to solve the background lag and high CPU occupation problems, to improve the overall site performance.