Various categories for TU1 already exist.

this leaderboard has ILs for obtain items, enter Nether, etc and it includes all main tutorial worlds as well including tu1

Piston refers to TU0 - 4

I think why you're confused is because pistons were added to the tutorial world in TU3. This makes TU1 and TU2 obsolete for some categories. I wouldn't recommend running with TU1 and TU2, as you're forced to do the tutorial each time.