[quote=Aragorn]
As a player of modded MC(Trust me, tons of experience with new world gen), new world gen will occur immediately after new chunks are generated. However, there may be some visible edges between new and old chunk generation(For example, you might get a giant flat wall of stone leading on to an plains biome). But other then that, it should be safe.
[/quote]

I now want one of these edges to happen

So I can build my home in it.