In post #30 you asked about what an observer in different reference frames would see when watching a football game. Since I wasn't sure what exactly you were asking, I gave three different answers in post #32. Then in post #34 you quoted from the first of those three answers and asked for clarification which I gave in post #36. Now you're asking about the other two of those answers and again, I don't know which one you mean.
But all along I'm trying to get you to quit thinking in terms of a frame of reference when asking what an observer sees because it has nothing to do with what a frame of reference is for. Here's how you should ask the question: "what does the hypothetical observer traveling for a long time at the speed of a muon see?" (my second answer) or "what does the hypothetical observer traveling with a muon see?" (my third answer). You then can use any frame of reference to analyze those situations, even the rest frame of the stadium, in fact, that is the one I prefer (your alternate definition of prefer).