The whole point of ex.15 (advanced turns) is to teach you how to avoid another a/c. It is not just a skills building excercise.
Emergency turns (Max rate.) would not be preceded by a HASELL check in real life, so why do them when practising? Do you do a HASELL check before you commence every turn?
HASELL checks are done pre-stalling, but in-between stalls, do a HELL check.
I don't do HASELL before steep turns, rather I tell the student that they need to turn immediately and hopefully they'll be able to do it without losing control of the a/c.