Support for Element Timing API (elementtiming attribute)

[cstavitsky]

Problem Statement

In some cases, Sentry detects LCP for items that are technically the largest, but are not the most important on the page.

Solution Brainstorm

The Element Timing API is used in cases when the largest element on the page is not the most important.

I would like Sentry to offer support for this, and include it in the LCP metrics.

┆Issue is synchronized with this Jira Improvement by Unito

[mydea]

We did (and are doing) a bunch of changes and improvement around LCP, so I am closing this for now. feel free to re-open if still relevant!