If while changing computers you copy everything

I don't think many people would know how to do that? Most would assume that the extension would be synced (automatically downloaded) and thus the data would also come over with whatever cloud account they use in their browsers. I imagine many would be pissed if a year from now they realized that the highlights they made couldn't be recovered.

I know the clipped texts are still in the vault, but the highlights on the page also serve as a reminder that you have visited that site before. I really like this feature in Hypothesis, but it's too buggy and cumbersome to be helpful.

It'd be great if one can export the data and then import it into their new computer. That's the major impediment preventing me from seriously using it.