I do hear what you are saying but to make a point I will be blunt.
Who are you to say the parse should be 5 minutes exactly?
I can put his parse length to 5 min and 27 seconds and it's about ~3390.
Taking a parse and cutting it at 5 min will just give whoever got lucky RNG at the 5 min mark have the highest parse. I personally don't really care if people clip the start of the parse, but I see a valid argument behind not doing so. But I see no reason to limit the time period to exactly 5 min.
I don't think it has to be 5 minutes; so long as everyone uses the same time frame. If that where to be 10 minutes or 7 minutes and 27.34 seconds it wouldn't matter to me. The point is, you can cut the log where you want to inflate the numbers.......that should not be happening (see my example above regarding golf for reason as to why it matters on a list such as this).