Schwern says that we don't know how far Bajor is from Earth, but actually the DS9 episode "Fascination" establishes the distance to Bajor to a precision of one or two hundred light years.
Did you ever hear of S Doradus? "The great and glorious S Doradus" as it is described in Mission to the Stars by A.E. Van Vogt. For decades popular astronomy books described S Doradus as the intrinsically most luminous star known, although today S Doradus is the least luminous star on this list.
S Doradus is in the Large Magellanic Cloud, a satellite galaxy of our galaxy, and is believed to be about 51,800 parsecs or 169,000 light years from Earth.
Most other stars in the list are in our galaxy, but some are in the Large Magellanic Cloud, or in the Andromeda Galaxy M31 2,400,000 light years from Earth, or the Triangulum Galaxy M33 3,000,000 light years from Earth. And one, NGC 2363-V1, is in galaxy NGC 2366 10,800,000 light years away.
The most distant individual star known is SDSS J1229+1122, a blue supergiant Type O star in the galaxy IC 3418, about 55,000,000 light years from Earth.
The Quadros-One probe might have had Starfleet type sensors capable of detecting objects at distances of ten light years or 20 light years or some other distance. But do you know what other types of instruments the Quadros-one probe might have been using?
Telescopes. Gamma ray telescopes, X-ray telescopes, ultraviolet telescopes, visible light telescopes, infrared telescopes, radio telescopes, subspace telescopes, etc., etc., etc.
How far away can 21st century Earth telescopes detect galaxies, quasars, etc.? The most distant galaxy ever detected by Earth astronomers is galaxy GN-z11, believed to be over 13,000,000,000 light years from Earth.
That is about 185,000 times as far away as Idran.
There is one problem with detecting distant stars in our galaxy from Earth. Our solar system is near the central plane of the galactic disc. Many dust clouds are also near the central plane of the galactic disc. It is very easy to see objects in our galaxy or out of it which are at angles "above" or "below" the central plane, because the lines of sight only go though short sections of galactic dust clouds. But looking along the central plane toward the center of the galaxy through 20,000 light years of dust clouds obscures the brilliant central bulge of our galaxy.
So looking at Idran 70,000 light years away along the central plane of the galaxy would be looking through about 70,000 light years of galactic dust to block their light. We would't be able to see Idran or any other stars within thousands of light years of Idran from Earth.
But the obscuring dust clouds are concentrated near the central plane of the galactic disc. Traveling "up" or "down" from the central plane would soon take a starship "above" or "below" the dust clouds and give it a clear view of distant parts of the galactic disc. The Quadros-One probe might have had to travel only 500 or 1,000 light years above or below the central plane of the galaxy to get a clear view of most of the Gamma Quadrant.
So we don't know whether the Quadros-One probe detected and studied Idran when it was 1,000 light years from Earth and 69,000 light years from Idran, or 69,000 light years from Earth and 1,000 light years from Idran, or whatever.
But obviously the Quadros-One probe had a fast enough warp drive, and carried enough fuel, to travel for 500 light years or 50,000 light years, or whatever the distance it actually traveled to study the Gamma Quadrant.