Interesting, Thermoquad idle mix screws come in different versions

I believe the bottom screw in post #1 with the shallow taper is from later TQs & is for tighter control [ emissions ] of air/fuel.
Taper doesn't really matter. Much ado about nothing, someone said.....
Bottom line: the tapered end, whatever it is, will form a gap with the exit hole....that is adjustable to provide the correct amount of A/F discharge for idling.