Hot take: cutting a window in a vintage case is cheating and most of you know it
I picked up a beige 1996 InWin tower at a garage sale in Tacoma for $10, stuffed a 4070 and a modern board inside, and it runs cool with the stock vents because I spent two weekends making real airflow paths instead of grabbing a hole saw. Half the builds I see here have a giant acrylic window cut in the side or the front panel drilled full of holes, and at that point you are not hiding anything, you are just wearing an old case as a hat. I get that thermals are real, my CPU hits 70 under load in a case with zero fan mounts, but the whole point of a sleeper is that nobody knows what is in it. So where is the line for you, mild venting and fan swaps or full on cutting, and does a hole saw disqualify a build from being a sleeper at all?