I’d say that standing should impose a limit on aiming.
Aiming below that point would require crouching or getting prone. This could cost extra move points or be totally free (only cost points to stand up).
This requirement would be shown in aiming menu. Trying to aim below that point would either not do anything (as if unbound key) or automatically drop player to the lower position.
Getting out of crouching or proneness would cost extra move points, making “run and gun” less efficient (it is currently pretty much the best way to utilize guns).
That way there would be no benefit to micromanagement and thus no tedium.
It would also allow easily defining “precise shot” etc. by explaining it as “the best accuracy you can achieve while standing”, “the best while crouching” and “the best accuracy you can achieve”.