Legacy portlets use JSP by default, so you could create some of these portlets and add your custom jsps to those portlets. By default, these legacy tools are hidden, so in order to use them you must enable them with Window → Preferences → General → Capabilities → Advanced → Development → MwS Legacy Portlets.
Regards,
–mark
#MWS-CAF-Task-Engine#webMethods-BPMS#webMethods