Found by catfighter:

"I connected a world to three separate foundations, setting each route to biotech (7) to maximize population. However, the world was uplifted to the maximum TL without using the extra tech levels! I reduplicated this on three different worlds, each importing from three foundations of varying TLs (from 7 through 10), and each world got 100% free technology. I only tried this when attempting to uplift to TL 7.

While it does not allow for control of TLs, it is awesome for sending shipyards up the tech tree at the speed of light! (Yes, not only did I get free tech, each world jumped up 5+ TLs in only around 2-3 dozen watches.)"