I preloaded last night but I actually want it on my SSD. I don't know whether to repreload or to use Steam Mover when it's out. I've never used Steam Mover, is it reliable enough to avoid redownloading?
In the past without using any other tool, I just moved the folder of the game to the equivalent path in the new SSD/HDD (which already has a SteamLibrary game)
Then I uninstall from Steam and say to reinstall in the new drive. Steam will verify that there are files already present and keep the downloaded files.