The engine does not include the historical 0.3 mapgen, so I can't just provide or enable it.
As for mgv6 vs. mgv5:
It was the easiest to get this up and working with v6 since it provides hardcoded biomes and structures very similar to what 0.3 had.
mgv5 might allow me to get closer to 0.3 but I will have to define all the biomes myself.
I suggest reposting this and future questions to Github because I don't check here often.
The engine does not include the historical 0.3 mapgen, so I can't just provide or enable it.
As for mgv6 vs. mgv5: It was the easiest to get this up and working with v6 since it provides hardcoded biomes and structures very similar to what 0.3 had. mgv5 might allow me to get closer to 0.3 but I will have to define all the biomes myself.