Some commercial boards (kitelement) use a scarf joint, so it's a valid way to go, especially with wood core boards.
I would imagine that doing a scarf joint is a bit more effort, depending on what equipment you have available.
Both the wavy cuts and the scarf joint makes the board halves slightly longer than they absolutely need to be - something to consider if you're using a big board.
For example, my 146 board has halves that are 73cm long. The inside of my luggage is 75cm, leaving 1cm clearance either side. If I had used a scarf or wavy cut then it would have been too long to fit.