I have never been to KL. Wife wants to go, but I have never seen a YouTube that made it look interesting to me. I have never been to luang prabang, so that look interesting to me. Everyone seems to love Japan too . Lots of options.
I would apply tonight. They ask for your hotel etc, so maybe book on agoda for something that can be canceled. Flight prices should be fine until after. I would look at Laos too, if you plan to stay a few days . That was my plan, but my friend talked me into vn