It's the other way round : you need this one…
https://tc.canada.ca/en/aviation/ref...-ac-no-401-001
My understanding, and I'm probably wrong, is that the Multi is an add-on. If you can fly the multi, the single privileges are automatic.
I believe that, for a Commercial MEL/Private SEL, you will get TC Commercial for both.
It's only the ATP that causes a problem. TC will only issue ATP for Multi. If you have an ATP SEL only, you would get a Commercial in the exchange.
Let us know how it works out. I've been waiting 2 years to get the conversion exam booked!
Good luck.