@Centarus.... The instructor doesn't advise to use stab trim or rud trim till after thrust reduction height
Every simulator instructor whether a current check pilot or not has his own personal views. These often contradict what is published in Boeing authorised manuals. From what you describe it is your instructor's purely personal whim that you should not use stab trim or rudder trim until thrust reduction. I have never heard of that trick before.
With any flight you use the stab trim to relieve stick forces just like ab initio flight in singles. IMHO your instructor is simply wrong in his assertion. Obviously you would not use stab trim during rotation but once comfortably clear of the runway it would be appropriate to keep the aircraft in trim. The last thing you need is fighting the trim changes until thrust reduction altitude.