It would be nice if Glyphs took stem width values from the dimensions palette so users do not have to enter these values twice. This would probably be very helpful for new type designers who might be confused about how to set these values up.
This is a bit more complicated. if you copy all values from the dimensions panel to the standard stems, you would end up with to many values. Usually the round and strait stems are quite close and you would want to have a standard stem just between the two. Because unifying the appearances of the stems is the purpose of the standard stems.
I’m confused about stem width values and their importance. I’ll crosspost to the Design forum for clarification from a good (typographic) samaritan.