So biomes obviously aren't a major thing to Potterworld and so largely it doesn't matter which biome everything is set as, aside from the colour of grass, water or leaves (and I don't even know if they change with the PW resource pack on). But one thing that does change is the weather. In colder biomes, it snows when the weather is set to raining, but in warmer biomes in rains. This video shows me flying over Hogsworth and shows how the biome changes a lot. This may not seem like a big deal, but it means that in some places it is snowing, while in others it is raining. The amount of times it switches between the two makes the whole experience seem glitchy or odd. I don't know if this is something that has been done for a specific purpose or if it was not on purpose, but I think the whole castle sohuld be changed to be the same biome, for consistency.