This is a long shot and will probably sound incredibly stupid at first (or even second and third) reading, but please hear me out.
In Endgame, Voyager traverses a transwarp conduit back to the Alpha Quadrant. We're told (by Reginald Barclay) that its aperture is less than 1 light year away from "Earth." Moreover, as Voyager is being escorted, we see in the backdrop a planet that looks very much like the Earth, with a prominent North American continent facing the fleet.
But we're never explicitly told that this is the Earth orbiting the star Sol. There is, in fact, another intriguing possibility: What is being referred to as "Earth" is actually "Earth Two" in the solar system FGC-347601 (from the TOS episode Miri), a planet that is a duplicate of Earth in terms of composition, especially geographically.
So, why wouldn't Barclay just refer to it using its "Earth Two" designation? Perhaps Barclay was trying to be politically correct by using its indigenous name, which, given Hodgkin's Law of Parallel Planetary Development, just happens to be the same as Earth's.
According to the map of Federation (circa 2399) space in Pic: Maps and Legends, the system FGC-347601 is in sector 02-AJ, putting it closer to the galactic core, and much closer to the Delta quadrant.
So, you might ask, why wouldn't the Borg put the exit aperture near Sol? After all, the heart of your enemy's empire is a very good location to attack.
Firstly, do we know what it actually takes to establish a transwarp conduit? Is it built in the same way that a tunnel is built, starting from the transwarp hub and slowly tunneling through subspace until the destination is reached?
Or, does it require another ship to be present at the aperture destination, in order to establish a two-way subspace connection? As far as we know, only three Borg ships (two cubes and one sphere) have ever appeared in the vicinity of Sol (four ships if you count the stolen transport in ENT: Regeneration). All were destroyed, and no on-screen information ever hinted that they had time to construct such an exit endpoint.
What's more, do we know how many ships can exit the aperture at once? If ships have to go through single file, an enemy fleet can concentrate its entire firepower on a single ship, destroying the Borg piece by piece.
It would be to the Borg's strategic advantage to quietly muster as many cubes as possible before dispatching an expedition, and putting the aperture in an obscure part of space (but which is nevertheless close to the heart of the enemy's territory) would facilitate that. It would fit the Borg's preferred military doctrine, as shown several times, which is to swarm an enemy civilization with many ships (sometimes hundreds or more). Everything we've seen suggests that they prefer to use brute force, and only fall back on using sneakier means as a second option.
Finally, the system FGC-347601 is located near the Romulan Neutral Zone (close to Starbase 10), making it a very convenient origin point for the Borg raider that attacked the Romulan and Federation Neutral Zone outposts. Alternatively, that particular Borg ship could have been the long range scout that built the exit aperture.
Thoughts?
In Endgame, Voyager traverses a transwarp conduit back to the Alpha Quadrant. We're told (by Reginald Barclay) that its aperture is less than 1 light year away from "Earth." Moreover, as Voyager is being escorted, we see in the backdrop a planet that looks very much like the Earth, with a prominent North American continent facing the fleet.
But we're never explicitly told that this is the Earth orbiting the star Sol. There is, in fact, another intriguing possibility: What is being referred to as "Earth" is actually "Earth Two" in the solar system FGC-347601 (from the TOS episode Miri), a planet that is a duplicate of Earth in terms of composition, especially geographically.
So, why wouldn't Barclay just refer to it using its "Earth Two" designation? Perhaps Barclay was trying to be politically correct by using its indigenous name, which, given Hodgkin's Law of Parallel Planetary Development, just happens to be the same as Earth's.
According to the map of Federation (circa 2399) space in Pic: Maps and Legends, the system FGC-347601 is in sector 02-AJ, putting it closer to the galactic core, and much closer to the Delta quadrant.

So, you might ask, why wouldn't the Borg put the exit aperture near Sol? After all, the heart of your enemy's empire is a very good location to attack.
Firstly, do we know what it actually takes to establish a transwarp conduit? Is it built in the same way that a tunnel is built, starting from the transwarp hub and slowly tunneling through subspace until the destination is reached?
Or, does it require another ship to be present at the aperture destination, in order to establish a two-way subspace connection? As far as we know, only three Borg ships (two cubes and one sphere) have ever appeared in the vicinity of Sol (four ships if you count the stolen transport in ENT: Regeneration). All were destroyed, and no on-screen information ever hinted that they had time to construct such an exit endpoint.
What's more, do we know how many ships can exit the aperture at once? If ships have to go through single file, an enemy fleet can concentrate its entire firepower on a single ship, destroying the Borg piece by piece.
It would be to the Borg's strategic advantage to quietly muster as many cubes as possible before dispatching an expedition, and putting the aperture in an obscure part of space (but which is nevertheless close to the heart of the enemy's territory) would facilitate that. It would fit the Borg's preferred military doctrine, as shown several times, which is to swarm an enemy civilization with many ships (sometimes hundreds or more). Everything we've seen suggests that they prefer to use brute force, and only fall back on using sneakier means as a second option.
Finally, the system FGC-347601 is located near the Romulan Neutral Zone (close to Starbase 10), making it a very convenient origin point for the Borg raider that attacked the Romulan and Federation Neutral Zone outposts. Alternatively, that particular Borg ship could have been the long range scout that built the exit aperture.
Thoughts?