I don't know, but whether they do or not shouldn't matter. They should design it so it can scale, 100k bookmarks is not really that big of a dataset for anyone, let alone G.

I don't see why they can't just fix this instead of asking him to revoke his plugin, especially if people are using it. It's needlessly removing a use case which may gain traction.

Of course they may know something I don't and which isn't mentioned in the article which makes doing any of this infeasible or undesirable.

Maybe they should just include the bookmarking in their search indices.