Understanding the giant tree didn't mean that humanity had a way to deal with it. It was the same problem as before, humanity was too weak. A level 2 space civilization at its peak facing up against a high tier space civilization with a four dimensional shield was like a unicellular organism facing off against humanity with nuclear weapons, the difference couldn't have been bigger!
Humanity's current technological level, excluding the Homo Evolutis cheat, was no different from a normal level 2 space civilization's. In fact, its level might be lower than other level 2 space civilization's due to its small fleet size. To counterbalance this, humanity had two secret weapons beyond the standard of low level space civilizations: the Gravity Cannon and the alien plant.
