Lightroom Classic: Keystroke to toggle Eraser Brush

Please add a keyboard shortcut to permanently switch to the eraser brush (and back).
Honestly I do not understand why this does not exist. I know it's possible to press and hold the Alt key, but unfortunately devices like the StreamDeck (small keypads with configurable keys) do not support "hold Alt Key". What I want to do is the following: I want to use an iPad with Apple Pencil (via the Astropad app) to work on my images and next to it I have a device like StreamDeck for the most used keystrokes. There is no room left for a normal keyboard in this setup and so a possibility to hold the Alt key is missing. It breaks the workflow if I have to use the mouse or pen to click on "Eraser" in the brush panel. Thank you.