I called up the SINP office to inquire about the extension on my nomination that is expiring in 10 days, while my PR application is still under review and to find out if I need to update them and request for a revised nomination in case the passport of my accompanying dependent has been renewed.
They told me to apply for both, extension and revision and provide the appropriate reason. They clearly told me that all applicants whose nomination is expiring while they have an application under processing, need to request for an extension, unless they have a work permit, which would automatically take care of the extension.
Accordingly, I filled up the form and requested for a revision and extension.
Hope this helps other applicants in the same situation.