I've got everything working in Options with 25.0.0 (That's Options and NOT Options+)
That's:
Mouse wheel (hold down) — pan
Horizontal Scroll Wheel — brush size
The buttons below the horizontal scroll wheel — Undo and Redo
Those are the only useful buttons IMO so far.
At the moment, when I start the computer and open Photoshop, the above functions are not working. I'm having to open Options and change it from All applications to Photoshop. I can minimise Options and the Photoshop functions keep working. We can obviously add Options to Windows Start menu, but I am not sure if we can make it select Photoshop. I'm thinking that if we have to do that manually every time, we probably won't bother. I think I could get used to the brush size and pan functions though, so I'll probably persevere. It's a shame that this is not working with Options+ seeing as that is the reccomened driver for the MX Master 3.
I made it work for Options+. When adding a new application, scroll all the way down and choose - add other application, then find the location where photoshop is installed (you can right click on its shortcut and go to file location, then copy and paste the diretory). Then you can use keyboard shortcuts to customize buttons. Its not the best but it worked.