Once upon a time, China was eager to settle borders with neighbors. At this point, I don't think there is much impetus to do so. Thinking of it, I don't think China would even settle with India without some sort of settlement with respect to Pakistan. If, after the settlement with China, India turn her full attention on fighting Pakistan, that would jeopardize the Belts and Roads initiative. In that sense, the current situation suits China just fine. It is up to India to make the settlement worth while.
In the future, maybe a decade or two, when the U.S. retreats from the first, then second island chains, the opportunity to settle the border with China would be lost. When the U.S. realize we are destined to be number two in two decades, it would be the U.S. that would seek to break up India to prevent a challenger to our number two position. If, at that time, India is still antagonistic towards China, the U.S. will have the acquiescence from China to break up India.
Sometimes you miss an opportunity, events can turn significantly worse down the road.