No thanks! Especially if that means player needs to travel so much to kill pirates and pathers before a colony burns to the ground. Next release, expeditions will cost reputation, so player might need to grind rep too. It is already hard enough to explore without an event that requires player intervention to deal with. Player needs to be at several places at the same time to deal with problems, but he can only be at one place at a time.
Setting up a colony very far in the fringe may not be useful due to extreme accessibility penalty.
The main appeal to this I see is more rare loot. For that, just pump Planetary Operations and raid factions' heavy industries for missing blueprints. As for exploring, you simply see more of the same, maybe holding out hope that you find more missing blueprints and maybe a better system to colonize if accessibility is not too low.
P.S. I would not mind an option for slightly bigger sector than normal size, but not many times bigger as shown in the OP's image. However, for something that huge, maybe portals to a stack of multiple sectors like dungeon levels, like normal space -> Hyperspace -> QuasiSpace in Star Control 2 or all of the star systems in Transcendence, could be handy, especially if there is a way to jump to different levels. (Might make Transverse Jump ability too powerful for this idea.)