btnx-config-0.4.0 introduced support for multiple configurations. This means you can create many different configurations for your buttons, and switch between them with the press of a mouse button. You can also backup and restore your configurations. The screenshot below shows btnx-config's Configuration Manager tab with a few defined configurations.

btnx-config's Configuration Manager
The left half of the screen is for managing configurations. The list shows all the configurations, their priorities, and which one is open. The '*' in the Open column specifies which configuration is currently open and being edited. You can open a configuration from the list by double clicking it. The priority numbers are for ordering the configurations. The configuration with priority 1 will start by default when btnx is launched. The order of the configurations will be significant if you bind a button to switch to a next or previous configuration.
Below is a list of the configuration manager buttons and their functionalities:
This button creates a new configuration. If you have a previous configuration open, btnx-config will prompt you whether you would like to copy the current configuration into the new one. If you select , a new empty configuration will be created. If you select , all values from the current configuration will be copied into the new one, including the detected mouse, it's buttons and their settings, and revoco settings.
This button deletes the selected configuration.
This button moves the selected configuration up in the list and increases its priority.
This button moves the selected configuration down in the list and decreases its priority.
This button backs up all the btnx configuration data and settings. It will prompt you for a location and filename where to store the backup archive. You can choose any name and extension.
This button restore all the btnx configuration data and settings from a backup archive. It will prompt you for the location and filename of the backup file. Note that it will delete all current configurations.
The right half of the screen is for managing to currently open configuration. Here you can edit the current configuration name, detect the mouse and its buttons, and restart btnx. Note that pressing the button restarts btnx with the currently open configuration.
For more detailed information on mouse properties, see the "Property reference" section.
The mouse properties section contains some information about your mouse. The Vendor and Product IDs should have been set to some hexadecimal value other than 0x0000 after the mouse detection. The Vendor and Product text entries are optional. You can fill them with the manufacturer name, ex. Logitech, and product name, ex. MX Revolution. These don't affect functionality, but could be implemented in future versions of btnx when it will possibly handle multiple input devices.