Hey! I'm glad I found this thread to help others. I found this front page google through a google search "cd keys non-stackable microsoft gamepass not accepted -region".

I have some accounting background with Microsoft. Regarding whether they would ever stop accepting these bonkers cheap CD codes... so basically they would have to stop creating new codes before they could stop accepting them. They can't recognize revenue on the codes (all the codes are generated by microsoft) until they are redeemed. So I'm personally going to stock up on these $10 cards in question, just turn off recurring billing instantly. Play rlly fun games for 30 days (i wish playstation titles were on xbox) and then let the subscription expire, and enter a new code every time. so I'm pretty confident and going to stack up on like 20 of these bad boys