Yeah, KLM's (extremely rude and condescending) chat agent first put me into Z and quoted a high fare difference. Refused to even look at I class.
I then contacted DL's chat and they reached out to their KLM partner desk and explicitly tried I class and came back with the same quote.
I don't know if it was handled by the same KLM people in the end or what, but I wasn't getting anywhere. That said, the ticket has been rebooked a lot of times by both Delta and KLM (including at AMS), so it was probably a mess.
At least we flew SEA-AMS in C class in the end, which would have earned 400% on VS, if I had been able to change my frequent flier number.
