D1 International carry-on Limits
First time traveling D1 this summer for a 3 week international trip. Trip leaving US is on a KLM code share. I was planning to travel with just two carry-ons. KLM allows two, but I noticed Delta only allows one plus a personal item. I have a hard side carry-on of correct size and was planning to use my 40L softside backpack as the second item. The backpack full with clothes will be closer to the carry-on size rather than the personal size limit. From peoples experience is Delta going to make me gate check the back-pack or are they likely not to care. One additional complication is I have to get to Atlanta via a short Delta flight (Airbus A321) where I will be in first class. Thanks in advance.