Sadly, I can confirm that Etsy does not integrate commercial Canada Post accounts with their labels, at least not if you sign up for Labels with the commercial account. Odd that you are still able to get non-domestic ones! Etsy suggested I open a new Solutions for Small Business account, which of course would mean my Etsy Labels would be substantially more expensive for a while, and I would lose my commercial account eventually, so all of my labels would be more expensive eventually. That would really suck for my customers.
I use Shippo for my labels; they do charge 5 cents US a label but it is still cheaper than only having a SFSB account, and they integrate with all of my sites. They even have a bonus if you get a referral from an existing seller (but I can't post that link here because that is against Etsy policies; just mentioning it so you know you can offset the costs).
@TickleYourWitch if you want Etsy Labels for some reason, I understand, but when I first got the commercial account, I was shocked at how much cheaper the tracked items were. That might have changed in the past few years, but if you want to compare rates between my acct & your Level 4, just let me know.
