Most of the time a correctly tuned 2 circuit Dominator works just fine for both bracket racing and throttle stop use. The only time it might be an issue is with an under carb stop with the throttle blades closed too far, too low of an RPM for the boosters to have a stable signal. With the carb blades at WOT and the stop blades partially closed the transition metering isn't supplying much if any fuel at that point either. I have had only one time that I've had someone with that issue, and I'm not entirely sure the carb was the problem. In that event a small amount of intermediate fuel might help. The boosters I use provide a better signal than standard Holley inserts, so even at lower RPM they still feed well. On a car with an inline stop I would have external linkage set up for 1 to 1, and with the carbs throttle blades functioning normally a 2 circuit would be my only choice.
As far as the EZ plate, I would size the carb to closer match the largest restriction, but a good Dominator should work if the engine can handle a Dominator.
As far as what others do, most I have reworked have the intermediate circuit way to rich for any engine, so hard to say what their throttle stop mods are...