Hello,
I am working with the TPS709 and there is a possibility the EN pin with go high before the VIN pin has voltage on it.
I notice that we are able to float the EN pin since it has an internal pull up on the pin with a protective Zener for clamping.
My first thought is that there would not be an issue with having voltage on the EN pin before the VIN but I wanted to double check to be certain.