I agree, this is important. If we send Gaia to Alpha Centauri, we will be able to measure the distance to the most distant galaxies. This is important, since astronomers still use indirect estimates to measure extragalactic distances, such as Cepheids or supernovae. Nobody knows how accurate this is.
But Gaia only has a meter telescope and sees very few stars and galaxies. According to calculations, in order to catalog half of the stars in our galaxy, it is necessary to observe up to magnitude 27. We need to know about all the stars in the Milky Way. For this reason, Hyper Gaia must be observed in the near-infrared, like the Webb telescope. It is in this range that red dwarfs are brightest and we can observe them through dust clouds. The infrared range reduces the requirements for the precision of the mirror surface.
Everything is simple here. Most likely, by mid-century, most data transmission from spacecraft will switch from radio to laser. This will radically reduce the area of solar panels. Probably by 2-3 orders of magnitude.
Thousands of Starlink satellites already use lasers to transmit data. Or compare the field of view of radio telescopes and the diameter of a laser beam on the Moon. The difference is close to a thousand times.
There the limit is close to magnitude 6. To cross Gaia, it is necessary to reduce the duration of exposures. This is a common phenomenon in astronomy. For example, for superproject LSST this limit is close to magnitude 16.