Sounds like a bean animal overflow.
1 full siphon regulated by valve
1 durso drain running lower flow
1 emergency dry drain.
As long as you have 3 drains I'd go for it. With a traditional 2 hole setup I would not, id use 2 straight standpipes
:edit:
From my experience a durso cannot be the active siphon. It will fill and flush and fill and flush and fill....
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