Ability to turn a flat world into a regular world

ok i gwt this might be really hard to code in, fine. but me and my friend have this one world weve had since we were a kid, and its been on a flat world. as we got older, we came to realise this was highly irritating and that we cant change it back to a regular world. what i thought of was a feature where you can turn flat worlds back into regular worlds, with a little feature that lets you select a building/creation or an area of blocks, and move it around into the regular world so that its not embeded halfway into the ground. say we get to pick a biome for the wrld to move to instead of the flats, and have some sort of stick tool in a 'creators mode' or a 'movement mode' (you know what i mean) where we can move the buildings from the flat world into our desired space on the regular map. i understand this might be hard to code. however it would make me and my firends, and probably alot of other bedrock/java players, very happy that we wont have to delete such a memorable and well put together world, and restart it completely