The recommended way to make an isolated change to a core JSP is to:

Create an Ext plugin to create a backup of the original JSP and extend the backup JSP

Create a hook plugin to override the original JSP using the tag to copy the contents of the JSP

Create a hook plugin to override the original JSP using the -override.jsp pattern

Create an Ext plugin to override the original JSP using the tag to copy the contents of the JSP