Rubber Dagger
I think your question contains all the key words, you were training for your CPL and your local school was teaching students (as they do). Each to his or her own level.
IMHO there's no point fighting it, and a certain height AGL doesn't really matter. If you've got a higher priority (like controlling direction in twins and feathering the dead engine), then deal to that, but if everything's tickety-boo then why not make it REALLY easy?
Also, sometimes it's easier overall to not trim fully. For example, in bigger twins that can, on one engine, actually accelerate at acceleration altitude (all alliteration) it's easier in the overall scenario of EFATO to initially leave a bit of back pressure on the C/C so that when it accelerates by 10-20kts, it naturally tends to pitch up/reduce back pressure required, all meaning you don't have to retrim. This makes it easier to fly whatever the procedure is while mentally going through the problem, memory items, ATC, QRH, etc.
My two cents,
1. Do what your instructor says, with the caveat dont' do nuthin dumb. If your instructor tells you something different to someone else at the same organisation ASK WHY. Someone's not standardised. Go to the Chief if you have to, it's their playground.
2. If it makes life easier, do it. When it gets hard it gets really hard, really quickly, and you need all the cards stacked in your favour.
Enjoy
C6