In the UI it would be nice to duplicate the selected connection, in the menu "With Selected". 

The copy would be set with the same name plus some suffix (_copy, _1, whatever) and it is useful for when you have a connection with all equal fields except something in a particular one. 
airflow/www/views.py
"""Get Dag as duration graph."""
        default_dag_run = conf.getint('webserver', 'default_dag_run_display_number')
        dag_id = request.args.get('dag_id')
        try:
            dag = current_app.dag_bag.get_dag(dag_id)
        except airflow.exceptions.SerializedDagNotFound:
            dag = None
        base_date = request.args.get('base_date')
        num_runs = request.args.get('num_runs', default=default_dag_run, type=int)
        if dag is None:
            flash(f'DAG "{dag_id}" seems to be missing.', "error")
            return redirect(url_for('Airflow.index'))
        if base_date:
            base_date = timezone.parse(base_date)
        else:
            base_date = dag.get_latest_execution_date() or timezone.utcnow()
        dates = dag.date_range(base_date, num=-abs(num_runs))
        min_date = dates[0] if dates else timezone.utc_epoch()
        root = request.args.get('root')
        if root:
            dag = dag.partial_subset(task_ids_or_regex=root, include_upstream=True, include_downstream=False)
        chart_height = wwwutils.get_chart_height(dag)
        chart = nvd3.lineChart(
            name="lineChart", x_is_date=True, height=chart_height, chart_attr=self.line_chart_attr
        )
        cum_chart = nvd3.lineChart(
            name="cumLineChart", x_is_date=True, height=chart_height, chart_attr=self.line_chart_attr
        )