GST/VAT in Microsoft-managed countries

I'll start by saying that I am not a tax / legal expert and my note should not be considered tax advice.

I am from Canada, and I have worked with partners from Canada, selling to Canadian customers before but I have not heard this before: "the way GST works here, we have to show the amount we receive from Microsoft as gross revenue"

Based on my understanding, because Microsoft handles the end customer taxation and remittance on your behalf - as you correctly pointed out in Scenario 5 of the docs - you should be able to consider the income you get in your bank account as Net income and not Gross income. Microsoft will provide reports in Partner Center that will show all details: net price, price + tax, tax collected, tax remitted, payout issued, etc.. so you can count all of those elements, and have proof that the tax collected was already remitted.