Those are good questions...
So basicly i understand this like this:
1) counter only tick when you are inside insance after event starts (if you will do one full 60min run inside instance the counter will be around 61minutes since there is about 30-60sec starting timer and this counts TOO).
2) it is NOT normalised score - so passing 40h timer will disqualify you (oposite to Ark Gold rush (where its +65 normalised score) or Merry Mayhem (where its +40h normalised score) where you MUST be inside instaces minimum of 65 (40) hours).
3) if you think that you can pass the 40h and the score will just stop updating - your most likely wrong. It won't and you will get disqualified (at least it worked like that in the past).
This thing is really worth underlining a lot since new players DO NOT know what happened in the past and may not understand the difference with "up to 40h" and "normalised 40h" event types which are obviously two different event types
.
Anyway - clarification on this on MA side would be apriciated since what i wrote is based on previous events and what heppened then.
Falagor