Mass Tile Operations (Before Instantiation?)

[Arkathorn]

Could someone with more experience with the worldgen code and the 'Map' class tell me the best way to perform tile operations en masse? I've found that trying to change eleven thousand tiles at once causes... minor lag and memory issues (what a surprise!). Perhaps modifying the tiledata before it's passed from the worldgen to the C-side Map, or some way of passing changes to said map in bulk?

 

On a side note, does anyone know of a way to trigger recalculation of the coastline collision walls without reloading the save?