Is it possible to overload default environment propgrammatically ?

Well,

I did not manage to understand it enough to apply it to my case, so I ended up with a dynamic setting.

I removed the use of Enviroment parameter in testRunner (now it uses default) and I provide as additional parameters the endpoint and credentials for my new environment.

Then I parse my requests and when I hit the first one, if data is provided and the endpoint is different from the default one, I update values with the parameters provided.

I noticed that changing it on one API impacts all the other APIs so I do it only once. As it is done with testRunner, modification is not persistent which perfectly suits my needs.

Here's the procedure :

in all my setup scripts I call configuration test case that I provide with the parameters and then I set the properties to the step

def endpoint = context.expand( '${#TestCase#endpoint}' )
def username = context.expand( '${#TestCase#username}' )
def password = context.expand( '${#TestCase#password}' )

... <checking the completness of data>

	endpoint = "http://"+endpoint
	
	// updating endpoint and credentials require to modify only once
	found = false 
	project.testSuites.find(){
		ts ->
		ts.getValue().getTestCaseList().find(){
			tc ->
			
			tc.getTestStepList().find(){
				step ->
				//log.info step.config.type

				if ((tc.name.contains("/m2m/fim/items"))&&( step.config.type == "restrequest"))
				{
					current_endpoint = step.getPropertyValue("endpoint")
	
					// update environment if it is not the one expected 
					if (current_endpoint != endpoint)
					{
						step.setPropertyValue("endpoint", endpoint)
	
						if( (username == "")||(password == ""))
						{
							msg = "the current Username and/or Password have not been set for environment $endpoint"
							testRunner.fail(msg)
							log.error msg
						}
						else
						{
							step.setPropertyValue("Username", username)
							step.setPropertyValue("Password", password)
							log.info "updated environment to $endpoint"
						}
					}
					found = true
				}
			}
		}
	}

Thanks for the help nmrao