New to editing here and I’m getting seriously overwhelmed by the range of factors in editing.

Basically I want to play in Bedrock and I want to be able to create a world using a height map that incorporates a custom made block.

I can create the world in Worldpainter and convert to MCWORLD but I’ve no idea how to include a custom made block. Is this even possible?

Would it be easier to do a block replacement after the world has been made?

Help! I’m going mad!