irishguy28

There should usually be more to consider here rather than just avoiding a seat selection fee (which is always in your power anyway - just don't select a seat).

And I'm not sure the way you've framed the question is valid. I understood this thread as being about a DL Diamond's experience with AFKL fare familes on AFKL flights. It's not about "gaming" your experience on Delta, or circumventing Delta's regime on Delta-operated flights. Just because AFKL do something one way, you can't make Delta dance to AFKL's tune by buying a Delta operated flight as a codeshare from AF/KL.

I'm not sure that you can circumvent the operating carrier's seating rules by buying it from a partner - you would still probably have to go to the DL website to select your seats, and therefore would be subject to their seating regime regardless of where or how you bought that ticket for what is, ultimately, a Delta-operated flight.

If you book a DL-metal flight with an AF/KL code, it could also have implications for your earning and/or (re-)qualification in your chosen Skyteam FFP. (While in Flying Blue it would have no impact on the XPs you earn, it could have a marked impact on the amount of miles you earn - probably to your benefit, certainly if you have FB status. However, the same might not be true for all other Skyteam FFPs - it's very dangerous to be so absolutist and throw in that word "always". In Skymiles, it could have an impact on your (re-)qualification - doesn't Delta have some requirement that you spend a certain number of dollars with them? If you start buying their flights from AFKL, can you state that that won't slow down a Skymiles flyer's ability to (re-)qualify for status in that programme? I must admit, I don't know much about how Skymiles operates, but I suspect that buying DL flights under their AFKL flightcodes would not be something a status-chasing Skymiles flyer would benefit too much from)