"Curve Back" is missing

[MikeGO2611]

I think this "improved" version of the Sapling Tree Generator is trully improved, it offers more control on many things, like the whorls (didn't knew I missed that option until I used this addon).

But one thing I miss is the ability to make branches (and trunks) in a S like shape using the curvature and back curvature. Would love to have that feature in this version.