The controlling factor in clogging in the plane isn't necessarily how closely you set the cap iron, it's the tightness of the mouth and the lack of clearance that can create (as in, it's better if the iron isn't up laser tight against the back of the mouth). Some later and lower quality wooden planes just aren't going to tolerate setting their cap iron correctly no matter the setting, I don't know if they expected craftsmen to finish the job of the planemaker back then because of the competition driving down the plane costs (and quality).

I haven't found it too productive to worry that much about the angle, and whatever the bailey chipbreaker stock setting is on a millers falls, that's the best tearout reduction I've gotten and also the nicest feel. I could be underestimating the angle that the chip hits that curved chipbreaker, but I figured it's probably closer to 50 than 80, maybe it's in the middle. I tried 80 with a japanese plane, where having the extra relief is useful (shooting in theory for the .3 setting vs. the .1). It's not as quick to set the double iron when it's retained by a pin and not attached to the iron, and the edge isn't visible. I still just found it easier to use a western plane and got better surface quality with the wester plane in anything where the planes would create tearout without the cap iron set closely.

I wonder what results they would've gotten if they shot the difference in distance and used an angle slightly above 50. I think that's a better setting, and it's easier to set and not have to fiddle with. It will still prevent tearout if you accidentally take too deep of a cut.