I would like to extrude a profile circle curve along a path and also be able to place additional profile curve(s) of different sizes and or shape - like is possible with the BiRail+3 tool. (so that one end is large and the other is small - etc)

I only want one path curve - not too and the profile curve to be closed.

Is this possible? I can not figure out how to do this, any thoughts appreciated.
thanks!