Nice set up! What made you want to go with the DAGR set up rather than co-witness with the offset BUIS? Id would have most definitely put that T-1 on an offset mount between the BUIS. Never-the-less thats a great looking set up there OP!
Beautiful rifle.
I concur that I would offset the red dot, rather then piggybacking it.
But that's a minor detail and trial and error will determine what you end up with.
Nice!!!