yeah, for the core the strategy is to keep the center purifiered up and let the rest of the zone do whatever.
Because the Core can spread it wherever. Doesnt happen As often when solo but def does happen.
So if you build a circle around the 6 lock bits and the inside bits from there it will hold at between 10-12% until you can clear the core
The goal of boxing it in was to maximize time to failure if I had to leave before it was finished. I see just now that someone else doing this turned out valuable, because I came back after a while and everything was overrun except the left edge, which was only clear because someone had cleared the left 1/3 of the map before.
But some hidden mechanic messed it up when I tried to box it in.
Yeah, like I said, it doesnt work that way on this map you have to go center out, because the core can spread it wherever it wants on the map.
Again, when you are solo the spread is suppressed, so while it can happen it doesnt happen often. This is why you didnt notice when you were alone but did notice when Imaginary joined as it happens more frequently.
Make a ring with the broken Anchors and fill in the inside is the best move you can make on this map if you cant take out the Core.