Comment 1 for bug 1618230

 Some CAD pgms have a remove unconnected pads option at plot time, but selective re-size for pours, would require a dynamic switch in PAD property, plus additional smarts in Flood to use the drill, if you did not want to use a specific Pad size.
 I think present flood, simply ignores drill/slot.

 Another way to control this, in a less automated manner, would be using the requested PadStack feature.
PadStacks very nearly works now in KiCad - you can define separate Drill & outer size, from F.Cu and B.Cu, and those process ok, but there are small issues around flood and connectivity handling of such Stacks.
It does something, just not quite the correct thing, when it sees concentric Pad Stacks.

 What you cannot yet do, is set an inner size, other than inferred via *.Cu

Some FAB houses like pads defined and to have a minimum annular ring to avoid drill tearing, so a total removal of inner stacks would need some care.

 I can, in present version, create & load a Stack-up fine with larger outer pads (F.Cu,B.Cu) and smaller inner ones (*.Cu) and that works, with the Thermal issue mentioned.

 The Fix required to thermal, is to get it to do 'less work', so it is a conditional removal of action, which should not be too hard to patch in.