Full Map Max Elevation or Faster/Larger Elevation Tools for Cave Creation

I've had success creating natural-looking caves by carving areas out of max elevation terrain with the room placement at plateau or water level (to still be able to add rooms inside the caves).
However, the process of using the "Raise elevation" tool for an entire map is laborious and time consuming.
Possible features to facilitate this:
Ability to speed up the elevation tools.
Ability to quickly raise/lower large sections of the map or the entire map to the maximum/minimum elevation.
The option to generate the entire map at max elevation initially (instead of just mountain peaks).