How do these numbers compare? fillet srf / blend srf options

When you do a fillet surface g2 you end up with the blue surface. If g2 is selected, the “tangent” slider is greyed out. what do these numbers mean?

If you create a blend srf, it has the exact same degree, but seems to be slightly off in the default position. The position of the points can be manipulated with the unlabeled sliders above (green). What do these numbers mean?

why is “1.000” not the same as default g2 fillet srf?

thx!


blue: fillet srf g2
red: blend srf (1.000)