I think that ConfigServer is the company that created the plugin for cPanel not cPanel themselves.
I recently noticed ConfigServer created interface for DirectAdmin not Plesk though. Maybe you should ask them for integration guys. Maybe Sarah on the forum over there can help with reason as to why. Maybe its not easy to implement as we may think.
Secondly as a system administrator myself I think using CSF via the command line and editing the confg files is easy aswell so shouldnt be such a big issue?
I contribute knowledge on their forums in the CXS and CSF sections alot so do many others and implementing those things are actually just copy and paste.
Also Bitninja and Imunify360 are far better options if you can afford the protection and since December last year looking at the type of hacks and bots causing trouble its something no host should even consider. We use Bitninja and will never look back.