Anders,
1) Instead of User Settings, you might want to use the Workspace Settings node (Preferences > CodeMix > Settings > Workspace Settings) so that this setting is a bit more limited in scope, and you don’t use this facility for all your workspaces.
2) We’re curious to know what your use case is – are you editing JavaScript files and you don’t like the live validation, or are yous seeing validation errors appear in your project for JS files that haven’t been touched? Why do you want to turn it off?
Just trying to understand so we can improve CodeMix behavior. Appreciate your time, thanks!