Sorry for my bad english, but I hope I explain it correct, so everyone understand it and can tell me if I’m right
(If you want a Top ranking)
Now you have to do a starting grind (first 4 clears) than in the last 2 hours you have to do a end grind…
… So in the time between the first 2 hours and the last 2 hours of each sub, you have to do nothing
… After the end grind, the new sub starts, so you have to do a end grind and a start grind in one row ( 4 hours and 7 clears in a row)
If you add the main nodes to that, there will be more than 7 clears in a row
It looks like D3 really want us to buy Healpacks like hell 
The good thing is, no need for VIP, it will not help you, if you have to do all clears in a row 
For Top ranking players it will be a rush