Paragraph opened as IFrame in multiple browsers

Hello Zeppelin, We were trying out Zeppelin. We created notebooks and then we share them as iframe to embed as dashboards in our app. We have JavaScript widgets that are bound to the Spark context to automatically refresh the data on input changes. Everything was fine until we noticed that when

Use embedded Spark for some notebook but use system provided Spark for others

Hello Zeppelin users, I was looking to configure Zeppelin so that it uses embedded Spark for some notebooks but uses system provided Spark for others. However it seems that the SPARK_HOME is a global parameter in zeppelin-env.sh. Is it possible to overwrite this setting at notebook level? Thanks