Apps script gadget setting 100% width and height bug?
The «leave blank for 100%» only works on the width attribute. You will have to determine some appropriate height for your script. I do not think there is a work around.
Furthermore, if you were able to set the height to 100%, that tells the browser to make the gadget fill 100% of the container (i.e. the page around the gadget). It does not tell the browser to fill 100% of the contents inside.
Configuring sil runner gadget — power scripts™ for jira 4.0 — confluence
The configuration screen is only available to Jira Administrators and System Administrators and enables them to manage the list of available SIL™ scripts. They can add, configure security and delete scripts or edit the parameters of a runnable SIL™ script.
To add a script to the runner, give it a name, description, and select a file containing the script.
You can also select a security option in the Gadget to restrict script usage to specific users or groups: