Thank you for sharing your thoughts on this. I think I see what you are trying to say, but I am somewhat confused by
Once on base the rate of descent is adjusted and flaps are set as required; even if 2nd notch of flaps is added no trim is really needed, as pitch changes are neglectable and flaps induced movements are absorbed with the joke while speed is kept constant, the attention is focused on final turn planning and height and energy management.
Do you mean to say negligeable rather than neglectable? If so it makes more sense even if I think you are mistaken. The amount of pitch change is rather type specific, what are you using as an example? And I suppose joke is a typo for yoke?
I suspect most early students will be forgetting about the trim anyway, rather than conciously not trimming, maybe we should just let it happen?