Geoffers - I'm not quite sure why you expect EHEST to include a sentence specifically for 139 pilots.
The document is fairly generic, as it has to be, and deals adequately with the different types and levels of automation. The advice about not trimming into turns is only in the section dealing with basic stabilsation mode with AFCS - nowhere else, so why would you assume they mean it applies to upper mode 4-axis?
The model illustrates that good (simple, intuitive, user‑friendly) design requires less competences and/or
procedural guidance (instructions) to be operated, and conversely that poor design requires more guidance
and/or competences from the user.
The model also shows that identifying only one element of the system in case of performance breakdown
is reductive and that overall system performance can by enhanced by improving any of these three basic
components, individually or in combination.
So, if the 139 has issues with the design (2 AP controls in close proximity causing confusion) then the answer, surely, is better training (unless you get AW to change the cyclic) - not adding a line in an EASA document.