Showing up the other team or rubbing it in, certainly should be avoided.
Good coaches, when they are, should be able to read the weak team coach, starting at the plate meeting. When the weak team coach says things like "let's just get through this" or "we need to count this game" or "wish we had a shorter run rule"; that is a clue that letting up or deliberate outs are ok. Even then, politely.
If not, play it out.
Of course, if the coach at 3rd is seen whispering to the runner and pointing to the pitcher, it is easy to be fooled by the runner at 1st stepping off.
