TWM induction has throttle bodies with two injector pockets each  for
the rotary.  48/50/55 mm available.  They did not have a photo but
something like this off the shelf needs checking out.  I gather it is
a new product.      Jerry

http://www.twminduction.com/ThrottleBody/ThrottleBody-FR.html

I don't see any Mazda rotaries in there. I see Miata. What they
do show is too short for our purpose.