FreeCAD supports raising placements to fractional power using ScLERP interpolation. The interpolation takes a helical path.
* as pow() method in python, to interpolate between origin and the placement
* as sclerp() method in python, to interpolate between two placements
* as ** operator in python
* as ^ operator in expressions
And a new Lattice2 feature based on it:
(the two big placements are inputs, the helix of small placements is the interpolation/extrapolation)