The second character doesn't have to be another ` - that option controls what you type for an unescaped version of your meta key. I use escape `~ and reserv

The second character doesn't have to be another ` - that option controls what you type for an unescaped version of your meta key. I use escape `~ and reserve `` for switching to the most recently used window. (It looks like I didn't need to specify that explicitly.)