I use 30#-40# superline which has the diameter of 8# mono on most of my spinning reels. I add about 3'-4' of 20# fluorocarbon line for weight to overcome the superline bouyancy.
My ultra light rigs have 20# superline which has a diameter of 6# mono.
There is zero reason to use sewing thread size superline as it has very little shock strength.
Humminbird Helix 12 SI, 1198c SI, 1198c SI, ONIX 10 SI NT, 360, RC-1