EasyApache 4 on cpanel servers provide rpm based packages for Apache web server and PHP. EasyApache 3 used to build Apache and PHP from source. This is a time consuming process. Easy update/build process take anywhere between 20 to 30 minutes.
Some times you need to build custom modules for Apache or PHP. This can be done by just compling the package/module from source. But this can break when doing EasyApache updates. If you have many servers, it is better build your own custom packages for EasyApache 4.
https://ea4.ninja/ provides step by step guide how to build your own custom EasyApache 4.
Cpanel documentation available at
Cpanel use Open Build Service by openSUSE project to make custom cpanel packages.
Open Build Service allow you to build your packages from source for different operating systems. Packages can be downloaded as binary or repository from Open Build Service.