https://www.sven.fi/en/catalog/mouse/rx-470w.htm
You can change buttons on the mouse itself, it doesn't even have a program for that. But it seems you can only choose from a limited list of options (copy, paste, print screen, Win button, F5, volume up/down, stuff like that), no custom shortcuts. Also not sure if you can switch between Bluetooth and dongle on the fly, or if it would forget the pairing. Tempted to get it just to mess around, not an expensive one.