For my own benefit, I created a script to flag any change in my Downloads folder then exported an encrypted .json to a USB. No temporary file was spotted when using the app. Configurations are normally stored in a .plist file, which I found contained no reference to any term or location I dreamed up that sounded relevant to a default location.
Given I also encrypt my computer’s main volumes I am not fussed; technically curious rather than operationally paranoid. For the latter group, CLI will definitely work. It is discussed on the Bitwarden Help pages