I would LOVE it if there was a checkbox that lets you dictate whether surrounding autotiles should be redrawn. One of the most frustrating things with VX/Ace/MV mapping imo is when you've spent time drawing in one group of autotiles (like tree tops), then you use another autotile to draw in an adjoining area (roof, building, trunks), and it redraws the original autotiles you had down.
I would find MV much easier to map with if I didn't have to redraw tiles all the time because the editor decides my drawing tile B beside tile A means tile A needs to be redrawn.
If the checkbox is checked (which it would be by default) it mimics the current behaviour, where surrounding autotiles are reshaped as you draw near them. If it's not checked, then ONLY the autotile you have currently selected would be redrawn, and it wouldn't make any changes to adjacent autotiles drawn with a different tile.