I've been after this (ability to delegate granular admin rights) for a very long time. We also recently noticed that the DECT/FXS container is not visible to any level of rights assigned to an extension, and only accessible via the main admin account.
So, if this is ever fixed, maybe a tick box per container to be allowed? Maybe other considerations, such as if you are a Queue Manager, you can add/remove agents from the Queue that you are the manager of? Update the polling strategy for the queue you manage?
So, whilst this could get quite complex, a great start would be the ability to open each section/container on the left side of the console. Some settings interrelate so they would need to be grouped together.