Osu! Lazer allows you to import beatmaps from a previous installation of osu! however if you have a slow or perhaps external drive with a lot of beatmaps, it may not be able to import most of them. Which is why this script written for Apple Silicon Macs zips and opens each beatmap in the folder to make sure they all get imported and the ones that don't can easily be identified and deal with afterwards.
Simply compile and run it with the argument of the beatmaps folder location where you want to import from.