It's certainly a good question. In my experience, if you are forgiven, you are forgiven. If it is out of active recovery, same gig. However, with the feds, they have a policy and that is "if your situation changes, it is your duty to contact them to advise. You MAY be required to commence repayment of that loan."
Now, if you are back in the workforce, making decent money, and benefiting from the education the crown gave you money for, then it's a no-brainer. You notify them - or risk getting caught. The gambit is real in such a case.
If you have an engineering degree, and the student loan has been set aside due to hardship, and you want to do what it is that you described, then the likelihood of them snapping your benefit off I think would be slim. But, bear in mind, if you say to them you are unable to work, and you are able to work, that also presents a potential issue.
Would you like me to try and see what I can find that is more tangible from the system as far as this is concerned?