I'll check my plate the next time I have it open and see if I can estimate how open it is on the current throttle idle screw setting. I'm sure it's just a whisker open because I recall that when I fitted the carb, I initially set the screw so it was just touching with the plate fully closed. Once I got it started, I opened it up a hair. Probably also depends a little on how big those grooves are. Eyeball says there's a bit of variation between the ones I've seen. At the end of the day though, if we get a good idle, that's the main thing : )
I couldn't be happier with my idle because I can start it at low idle even in cold weather, and I like that for its (hopefully) journal saving properties