Here's the rules for a WT11/WT21 award ticket from the DL site (my emphasis in bold)
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*Travel is via Delta or any AeroMexico, Air France, Alitalia, Czech Airlines and Korean Air operated flight and must be in a continuous global direction, either eastbound or westbound, no backtracking permitted.
*Travel must terminate in the same country of commencement but not farther than the original point.
*Stopovers include a maximum of three per continent not to exceed six total per award.
*Open-jaws are permitted and count as a stopover.
*If a flight is operated by a codeshare partner, it must permit local traffic between the stopover point and the destination.
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With this clearly stated, it is clear that back tracking thru a connection city is not permitted, so the multi-connects thru CDG and Seoul would not be permitted. Also note that the CDG-London would not be permitted since it tracks back in a westward direction while travelling east. I recommend an atlas be in hand when choosing your route to avoid back tracking.
Enjoy your BE trip! I have been planning to do just this for a few years now. Miles are in the bank for the two of us - it's just getting the free time to take a couple of weeks off and really enjoy the trip.
And when you're done travelling, please do write a trip report of your experience with the different airlines and cities
GMF