Is it true that enlightenment is equivalent with perfect knowledge?
In buddhism, Enlightenment is the "direct knowledge" about suffering, the origin, the cessation https://www.accesstoinsight.org/tipitaka/sn/sn56/sn56.011.than.html

the four immeasurables  is just how to get to Brahma world, like here https://suttacentral.net/mn99/en/sujato  so it is not Enlightenment. When you claim that the four immeasurables  is Enlightenment you are a hindu and that's totally wrong in buddhism.

So you are mixing hinduism and buddhism. In hinduism the path to nibanna is to generate merits over and over, same thing with the jains. They have to burn up past bad karma and create lots of good karma..
But that's very wrong view.

In buddhism generating merit is useless to get enlightened. Merit gets you a good birth and that's all. In buddhism you need to know about suffering, the origin, the cessation and the path to the cessation of suffering.
So do not confuse the path of merit, the path of Enlightenment and Enlightenment itself.