I have 3 computers (2 desktops and a laptop). I use Dropbox as my "file server".
Can I change the profile location from C:\Users\john.config\joplin-desktop to a directory on DropBox? Or should I sync the other two computers to my primary desktop?
/joplin-desktop contains much more than just your data and is necessary for stable work of Joplin. However, if you would like to sync devices some different data, I recommend trying to use Profiles feature