While I understand the desire to control Eos completely, I learned to work with this and have come to the conclusion that I'm perfectly fine with it.

This way I can focus on the tank, and Eos will heal either
1. the tank
2. stragglers that I don't have the time for at the moment

When healing gets frantic I usually don't have the time to heal non-tank party members anymore, and Eos does that for me. Lazy? yes. Does it work? most of the time. If I have the time to heal others I do, if not I leave them to Eos or the WHM.