Affinity Photo 2 Erase Tool Behavior Wacom Pro Pen 3

[dull.gaze]

Coming from Photoshop as my primary digital sketching tool and still getting familiar with Affinity Photo 2. I've searched for a variety of erase-related topics but haven't found a solution to this particular issue. I'm also using MacOS on Sequoia 15.0.1

I typically have the Wacom Pro Pen 3 buttons mapped accordingly (see attached image). Erase > Pan/Scroll > Right Click

The experience I'm looking for is that the pen primarily draws with a selected brush and when I press and hold the button mapped to Erase that it erases these marks and defaults back to the primary brush when I release the button.

The Pan/Scroll and Right Click buttons behave as expected, but the "Erase" mapping doesn't seem to react (continues to make marks as the primary brush). I've also tried mapping a keyboard shortcut to the same button with "E" for the default erase tool mapping but it doesn't default back to the primary brush tool after releasing the button and subsequent presses cycle through the rest of the Erase-related tools (Background Erase / Flood Erase / etc).

I feel like I must be missing something really obvious - does anyone have advice/suggestions? Thanks!