See Immersive Reader Mode in Action
Check it out, just move your mouse to the top right corner of your screen and wait 1 second to auto activate Reader Mode.

Let’s just say you are lounging back in your chair with a hand ONLY on the mouse and want to activate immersive reader mode without clicking a mouse button or using a keyboard. Let’s setup a mouse gesture with the following criteria:
- Use AutoHotKey
- Only send key if active window is a browser
- Detect mouse position
- Add a cooldown timer to only activate every 1 second
- Don’t need to click a mouse or a keyboard
- Active Reader mode when moving mouse to TOP RIGHT corner of monitor
; ---- AUTO READER MODE ----
#Persistent
CoordMode, Mouse, Screen
SetTimer, CheckPos, 750
return
CheckPos:
if !WinActive("ahk_exe msedge.exe")
return
MouseGetPos, x, y
if (x = 1919 && y = 0)
Send, {F9}
return