The middle way of the Buddha was not to be, for example: not too loving, not too hateful. It was not really the middle way but the non-dual way, a way where oneness was and dual notions (always rooted in mind) were not.
The middle path, the path of Tao, was no such middle path and no such path at all. It did not go or lead anywhere nor skirt the border between polar extremes, it was instead the non-dual. Not a way at all.
Zen, Ch’an or other words for meditation were not intended to say you must meditate and perhaps lessen or balance extremes in mind, but they were instead naming the non-dual mind, the Buddha mind, the mind of the person of Tao.
Balance is between extremes whereas non-dual does not even have the split.