[5.x]: asyncCsrfInput true or false negatively impacts page speed

[joepagan]

What happened?

Description

• Setting asyncCsrfInput true - Creates an extra network request to the network dependency tree on page load which negatively impacts the LCP Core Web Vitals metric
• Setting asyncCsrfInput false - Forces a no-cache server response header which forces a static caching layer to be bypassed, negatively impacting TTFB.

Steps to reproduce

1. set either setting
2. run a pagespeeed/lighthouse test

Expected behavior

• For a craftcms website to not to be negatively impacted by a feature we cannot control
• asyncCsrfInput false should instead never set a nocache header - then we can be in control of when it should fetch a CSRF, e.g. when a form is "in view"

Actual behavior

• No matter what setting is set, it negatively impacts performance

Craft CMS version

5

PHP version

8

Operating system and version

No response

Database type and version

No response

Image driver and version

No response

Installed plugins and versions

[linear]

CMS-1663