This is a list of ideas, each of which has a performance/accuracy trade off. We'll only pursue ideas that will provide more info about the feasibility of index-based CE, based on our initial findings from the perf/accuracy testing. We will re-run the perf/accuracy benchmarks to validate the below changes

• Investigate searching into leaf pages only for traversals which end on the same leaf
• The prototype does two rounds of walking the tree. The first round just detects edge cases (empty range). The second one is used for CE calculation. We should investigate doing just one.