The number of potential links in a graph of n vertices scales like O(n^2). That does not mean that the actual number of links in the knowledge base should scale like O(n^2). However, it could mean that the overhead work to maintaining and building the connections in the knowledge base becomes unbearable. That is, the solution is not saving time anymore. Solutions like these need, imo, really good link prediction solutions to make it easier to manage them.

Are any of these personal knowledge base solutions offering link prediction as a feature to alleviate this problem?