Years ago when considering the Delta Platinum Amex I didnt get it because the companion certificates couldnt be used for First or Comfort+. Rehashing the same issue it seems like now it can now https://frequentmiler.boardingarea.c...w-upgradeable/

However, this article merely talks of free upgrades. My fiancee cant fly coach due to an injury she had years ago. So we only book FC/D1 or Comfort+. Using Companion Certificate on Main Fare and hoping for upgrade is not in our cards because we wont fly if she is stuck in coach. Therefore, I was wondering if I could use the Platinum Companion Ticket on L,U,T,X,V fare then pay the difference for W (Comfort+) Fare?

Would the website let me do that now? Or am I still restricted? Curious about people's success with this.

Delta "paid" upgrades are quirky because a W Ticket will be $500, with a FC ticket being $700, yet after you book and you get that "Upgrade to First" ad on the app its never $200 (the original difference), its usually double price which makes no sense.

Thanks in advance.