I fully agree, and while Devers at 1B does make the most sense, playing Story, Campbell, Bregman, Abreu. Duran and others at DH seems almost as ill-fitting as Story at 1B.
Ref makes sense at DH vs LHPs, and it would improve our defense by playing Anthony or Rafaela in RF vs LHPs. Rotating the others as "rest days" vs RHPs is fine. (Abreu would never DH as a rest day, since he gets his rest on the bench vs lefties.) Romy has been hitting lefties well, too, but with Devers at 1B and Ref at DH vs LHPs, he'd be the off man out- no biggie. If the plan is to rotate Campbell, Anthony, Duran, Mayer, Story and Bregman at DH that is about once a week for everyone. That could allow them to never need a day off from the line-up- just off on D. The issue with Story being too weak a hitter to play 1B also applies to DH, so maybe he gets actual days off, and it becomes a 5 man rotation vs RHPs, only. That seems manageable, doable and maybe even beneficial to all involved.
DH: Refsnyder vs LHPs/ Campbell, Mayer, Anthony, Bregman & Duran v RHPs- every 5th time
1B: Devers
2B: Campbell & Story or Mayer
SS: Story or Mayer
3B: Bregman & Mayer or Campbell
LF: Duran or Anthony
CF: Duran or Campbell (Rafaela back-up)
RF: Abreu or Anthony (Rafaela/Refsnyder back-up)
We basically have 7 players (Bregman, Campbell, Duran, Story, Mayer, Anthony and Abreu) for 6 positions plus DH vs RHPs, but we know Abreu sits vs LHPs, so it becomes a perfect 7 for 7 match (counting Abreu and Refsnyder as one.) Devers would rotate to DH, too, and who plays in his stead would be determined (Romy, Wong or a current infielder.)