Property expansion in environment endpoints

1. We have a project property called 'domain'. Also I see something as domain in the con:endpoint tag. Will these both things clash when I want to execute tests on specific environment using option -E ?

2. Is it recommended to use endpoints using variable expansion i.e ${project#targetEnv}, as we done in the above image or should have actual values like -dev-a etc specially in the environments tab?

I am asking these questions because when I pass environment name in the parameter -E from our scripts, it is not picking up respective project properties. As a result, endpoints are not getting resolved correctly.

Can you suggest better recommendations ?