I reverted this part of your change and added a comment. We can't do a nextKey here on an exclusive lower bound, because if the last column is variable length, we'd be incrementing the key (since there's no terminator). If we add a terminator in this circumstance, then when we extract the value in schema.next the terminator wouldn't show up (since we never include the terminator).

We always have a lower inclusive, though, so I think we're ok