This had me wondering - well I made a call to CIC 1-888-242‑2100 and a nice fellow named Richard answered. I posted the questions I asked and his answer while still fresh on my mind:
Q: I have a question on IMM5562 - Supplementary Information - Your Travels. I have recently submitted my PR application a few months ago and submitted this form filled out up to the travel information I have before I sent in my complete application. I will be travelling out of the country in a few weeks time and I would like to ask if I need to resubmit this form after travelling to update my PR application.
A: Were you asked to resubmit this form by CIC?
Q: No.
A: Unless specifically asked by CIC to resubmit the form to update the information on your application - you do not have to do so. All your travel information in your current application is based on your travel history up to the date of your application filing. Anything that comes after is not related to the application already filed.
And he reminded me that specific instructions to submit any additional info in relation to the current application will be sent by CIC if required and I don't have to update my application except for change in status/info (marriage, spouse, new child , contact information).
/hope this helps...