Probably most admission readers will not be familiar with specific courses or policies at an applicant’s undergraduate school, unless they themselves by chance happened to attend that school in the past. So your gut feeling that extra rigor in course selection beyond (a) fulfilling required and recommended pre-med course work for that medical school, (b) not having “repeat” courses unless required by (a), and (c) not having any pre-med course work taken in a disfavored situation (e.g. in a summer session at a different school), may have little or no effect may be reasonable since the extra rigor may not even be noticed by the admission reader.