Two (plus a space) for me. if you’re on iOS - and I think Android - if you hold the “123” modifier and then _slide_ to the “!” and release, it inputs the character and then switches the keyboard back to alpha. one touch.
Android:
0. slide back up to the search bar
1. touch the search bar
2. touch "space" (optional, I guess)
3. touch "?123" modifier
4. touch "!"
5. touch "?123" modifier
6. touch "g"
7. touch "enter" or "search"