Derrick Hammer

This plugin will show you all the documents rendered on the current page, and their elements in nested accordions. It shows their unique element ID, type, and how long it took to render it and any children
As this is an extension to Debug Bar, it must be activated as well.

Debug Bar Elementor

Output debug information regarding elementor on a page such as elements and performance data. Requires Debug Bar

Forge12 Interactive GmbH

This plugin will track the load time of each plugin, javascript and css file 
to help you optimizing the performance of your WordPress site. It will help you 
to figure out which plugin / resource causing the slowness of your page.
Track time for:
<ol>
<li>Core</li>
<li>Theme </li>
<li>Plugins</li>
<li>Resources (JavaScript, CSS)</li>
<li>External files</li>
</ol>

F12-Profiler

Excellent! After P3 doesn’t work with PHP7+ anymore, F12 seems finally the one stepping in to fill that gap.

Update [18-Jun-19]. After some small contributions of mine to the dev efforts, the plugin developer has decided to add me to the team, long after this review was written.

Finally an alternative to P3

Trace the execution time of plugins, themes and core files to find the bottlenecks of your system.

Debug Bar Elementor vs F12-Profiler