Crop/extend mode for transforms

[ftlbiped]

Problem
Often while painting my landscape from scratch (I prefer doing this to generating a random landscape) I realize I've painted myself into a corner - literally. By which I mean I've run out of room on one edge. Or conversely I'm just left with a ton of ocean off one edge of the map. If I want to resize the map, I've got to use transform, scale the map, then drag the new map into the right position (roughly, hoping I get it right), then go back to global settings to change how big the map is and where it is relative to the globe, so my biomes and climate and everything stays the same.

Solution
It would be fantastic if the Transform feature included options to just extend or crop edges by a certain amount, leaving the current map's location and size the same relative to the globe.

Alternatives
If not this, I think I'd just have to do a bunch of math with the transform and global settings to try and get it right. But I don't relish those calculations, and I usually end up just trying to redraw the map into the correct frame from scratch.

[Azgaar]

Hello, it would be nice to have, but I'm not making that significant changes before version 2 (code refactoring)