A lot of fun.
I understood what you meant, the wiki on The Deep page, sums it up more simply and technically:
Quote
With two players, one flags their first three heroes to gate one (far right) and flag the rest of the heroes back at the wooden gate. Once all two/three players are inside Room Two, unflagging the heroes will cause them all to rejoin the players after a short delay.
To test it, just go to the beginning of The Deep, Flag the heroes on the active teleport, then cancel the flag and it works. Just for fun, yes you do it 4 times and get stuck at the beginning of The Deep, no more active teleport, kind of a bad joke 
Now technically? I do have a theory that covers what i said in point 2 of my previous message ->
It's interesting to note that they reappear at the original location intended as the starting point (coord. X/Y) for each "zone" separated by teleportation. Before the 4 teleports, in the starting "zone" where you appear after downloading The Deep instance. After the 4 teleports, they arrive at the teleport circle. Heroes were not planned when The Deep was coded. As pointed out in point 2 of my previous commentary, heroes are sometimes capable of overriding the normal physical rules of the game. Here we have an example that is both extreme and explicit. So, the heroes are trying to reach you, they're looking for the shortest route, the rest is of secondary interest to them. I'm talking in terms of the code resolution that governs GW. And here, the game's code not having provided for it; hero functions in The Deep, particularly on teleporters that don't work as they do elsewhere. That is, when you engage them, they don't automatically teleport your heroes with you. The game, the code, gives them access of functionality, to use the teleportation function to join you. Right on the nearest matching point to you in this zone, the vertical teleporter.
That's great, but it only works because The Deep has unique teleports in the game. At least i think so, i can't think of any other example where you, as a player, can use a teleport, which won't also teleport your heroes automatically with you or whether they're on the map. And even in the case of other similar elements, without teleporters in The Deep, it's more the code that governs it in its entirety that's lacking and enables this feat, not just the teleporters (to ponder...)
Edit: On reflection, it's the same principle as when you remove the Flag and the heroes are far, far away, coming back to you at compass level in a matter of seconds. Except that The Deep seems to calculate these distances differently, between you and him. As a result, even close heroes are teleported.