If you have control of your data, then you can delegate to doctors, EMT or other agents.

I want my doctor as agent to delegate to other specialists without consulting me. Most of the time it isn't needed but I don't want to be bothered for 'just double checking this is nothing' which should happen at times.

When you say, "I want", you need initial data control to give that instruction.

You can delegate to your doctor the right to delegate to other specialists without consulting you.

Other humans can delegate to the agents of their choice.

This is why the first step is for you to have control of your data, then you can specify/revoke who-does-what with it.