Hi,

I have adapted version 0.4.1 so that it is using a multiline textbox as input interface; I find it useful when a larger amount of code has to be inserted into the page’s header.

You can download it from here:
https://tilusnet.com/src/wp-plugins/add-your-own-headers/with-textarea/add-your-own-headers.zip

Unfortunately up to this point I was unable to find a way and to get in contact with the original author of this plugin (uberdose) and perhaps make the update available on WP’s plugin page.

https://www.ads-software.com/extend/plugins/add-your-own-headers/