Is it possible to select one of the faces of an object and then scale it?

 From:  Frenchy Pilou (PILOU)
10091.27 
In fact in your special case (in fact for any case) :)

If you make 2 Flow (or more if you have a tortured object) that works perfectly! :)

I start from the first result above after the first Flow yet made!

Do you understand the subtility ? There are 2 "Flow" one view TOP, one view SIDE...

Here the second! (view side)
Et voilĂ ! Happy new year!

EDITED: 2 Jan 2021 by PILOU