But you left out the most important factor - options.
Duran can go to Worcester. Refsnyder and Tapia cannot, at least not without clearing waivers. Of course, demoting Duran to Worcester won’t get Duvall back on the 40 man roster.
Someone has to go. Most likely, Ryan Sherriff, as he has cleared waivers before so a DFA likely won’t hurt the Sox pitching depth. Other candidates include Justin Garza, Rich Bleier and (a longshot, admittedly in) Refsnyder. Not likely they DFA Ref, but it’s certainly the cleanest move…
I suspect they demote Duran and DFA Sherriff.