After reading some of the recent experiences, I went in with low expectations. My ORD-AMS-CPT flights showed I0 Z1 on EF so I was concerned that the Z space was phantom to begin with (but I could book the flights on the DL flight numbers on DL.com in Z).

I fed the chat agent my PNR noting that I believed there was Z space and she thanked me for doing my homework. She was quickly able to snag the last Z space (I noticed on EF, it went down to I0 Z0 immediately thereafter). She indicated that she had to reach out to her support desk as she doesn’t do KL GUCs frequently but this only took about 10 minutes. I then saw I was now confirmed in business ORD-AMS-CPT with the ticket reissued.

Credit where credit is due, that was the easiest it’s been to use one of my GUCs. If only it were always that easy.