Yep, topological naming solving is a hard problem to solve. It took FreeCAD many years to get it to work correctly. That's why I went with indices for this version. You can also use filters like extrusion.endFaces(face().arc()) to get only arc edges.

Regarding the picking; that's exactly the region picking feature in this screenshot: https://fluidcad.io/img/region-extrude.gif

When the user click on a region we insert a 2D point, then the extrude feature will find the nearest face. I have experimented with adding this picking logic to selections too select().pick() which will probably be merged in future releases.