Fuji, for a bog standard steep turn, a HASELL check is unneccessary, it doesn't matter if you are going for 10 or 1000 degrees of heading change.
Lookout should be done before, during and after any manouever, negating the need for a HASELL check.
What does a HASELL check look for?
Height- sufficient to recover by a given height above ground.
Airframe- correct configuration.
Security- Loose objects, harnesses.
Engine- T's and P's, carb ht, mixture
Lookout- to clear airspace, especially that which is below you if doing Aero's or stalling/spinning.
Location (Clear of Airfields, Built up areas, Controlled Airspace, Cloud, Danger Areas.)
Most of this is irrelevant for a steep turn. The lookout is important, but I am suggesting that you do this automatically.
Can you give me a reason why all the other checks are essential to the steep turn exercise?