it's possibly that the Bend of Time is a gate. When i say "gate" I mean in the same fashion as the sea of eden/dead sea, and Terra Tower/Dinopolis.
Best and easiest way for me to explain this is as such.
Chronopolis wasnt physically transported to El Nido, what you see in CC is a kind of giant gate, and when you pass through it, you end up in the relative time period where Chronopolis is. This gate has to be able to transport more than 3 poeple, so there needs to be a nearby thing to prevent people from breaking the law of the conservation of time.
Now, think of time travel as a capacitor, and the travelers as electricity, and just like a real capacitor, applying energy will change the direction of electrical flow from the line to a ground wire, in this case, the end of time.
combing capacitors allows you to change the electrical output, making it possible to do all kinds of things. Computers do this. It's possible that by applying a point of LESS resistance, it allows for less limited travel between Chronopolis and El Nido, while also gathering entities bound for the Tesseract.
Thus, you might be able to think of the Bend of Time as a kind of temporal router that allows people to make use of the special gateways of Chronopolis and Terra Tower, by intercepting travelers and routing them to the correct location, much like a ground wire in a capacitor is used to allow or disallow electrical currents on the certain line.
