I'm not sure about not addressing it in an LOE, my own take is that they will already know you have the misrepresentation ban, so the LOE is getting ahead of that, and trying to do some damage control, and just acknowledging that you made a mistake in the past and are regretful of it. But the lawyer would know better about how it works in practice especially in Quebec at the provincial level. Maybe get a second opinion if you can just to confirm if possible.I talked with a lawyer recently! he said: 'it is up to officer to overlook the ban and let it go! or simply reject the application.'
For sure, I will clearly mention my inadmissibility in the related part of forms! so I do not think that there is a reason for getting another misrepresentation and ban!
The lawyer said to me not to include LOE (asking for forgiveness etc.) ! he said send your application same as an idiot and do not provide the clear reason to the officer for rejection!
So up to now, my conclusion is:
Writing a cover letter and showing the all money and scholarships that Canadian government paid me to get educated. And show my interest to come back to Canada in the case that they provide me a PR!
What is your idea! I am wondering does it really make a difference if an immigiration professional apply instead of me?!
I do understand their rational but they will already know about the ban regardless.
As for whether you should go through an immigration professional, generally i don't think it's necessary but because you are applying through Quebec, i've heard that the system has devolved into a bit of a mess there nowadays, and having a lawyer or consultant to check on your file, prevents your file getting neglected.
Make of that what you will.