Great find !
Add $1000 and enjoy a full RTW with UNLIMITED FREE STOPOVER, FREE CHANGE and FREE CANCELATION (and more miles earned as it would be a D fare). Better than a MPM DONEx !
All fares are valid for a 12 months trip
Let's play !
Edit : the HIP (default if non specified) rule makes the ticket re-faring at each stopover, so no unlimited free stopover. But you can still manage to get long (<24h) free layovers with OP cheaper fare