Another solution: Create the shortcut of where the launcher is, go to properties, change the target to something like this:
"C:\Program Files (x86)\Blockland\BlocklandLauncher.exe" -profilePath "C:\Users\<user>\Documents\Blockland\"
If you have any issues in the location create a folder, usually that fixes it. This is how I have 3 different blockland folders (default, client, server)