If the aliens are sending interstellar ships to colonize nearby systems, have no biology or medicine, have no nuclear energy or chemical propulsion (they built a tower on their low gravity planet and launched a solar sail based craft from it with the equivalent of a slingshot for their space program), and have quantum computers, they don't have a level of technology.

Well what does no medicine mean? A lot of medicine would work fine without understanding genetics in detail. Blood donors and antibiotics are both examples. Also do normal computers not count as technology? Why not? Assume that we somehow interacted with an alien group that fit your description. Is there nothing we could learn from them? I think not. For one, they might have math that we don't have. They might have other technologies that we lack (for example, better superconductors). You may be buying into a narrative of technological levels that isn't necessarily justified. There are a lot of examples of technologies that arose fairly late compared to when they necessarily made sense. For example, one-time pads arose in the late 19th century, but would have made sense as a useful system on telegraphs 20 or 30 years before. Another example are high-temperature superconductors. Similarly, high temperature superconductors (that is substances that are superconductors at liquid nitrogen temperatures) were discovered in the mid 1980s but the basic constructions could have been made twenty years before.