Thanks for posting that. There are some keyboard combination keys that at this time are not doable on the Quick Keys.
The Win+Alt+b is one of them. As you notice, you can press the Win+Alt but when you press the "b" it activates the HDR mode toggle On/Off. There are a few key combos that do that and our driver team is working on a way to allow you to be able to enter those key combos and be able to assign them to a Quick Keys or Pen button.
Please stay tuned for an update on that one.
I have the Quick Keys Remote and wanted to map the Windows HDR shortcut "Win+Alt+b" to one of the buttons but it will not save when I enter the keystrokes. The Win and Alt key will register but when I press "b" it won't add in. If I try a different combination, such as "Win+Alt+n" it does register. I've looked through guides and nothing I've found has worked yet. Has anyone else encountered this and found a solution? Thank you!