Thanks for the continued feedback. Attached is v8 addressing your nits

on patch 2:

- Reworded the commit message to say "the same outer-bounds-based

  estimator can be reused" instead of implying the code is just

  duplicated.

- Made comments in multirangejoinsel type-neutral where they

  unnecessarily said "range" (e.g. "bound histograms" instead of

  "range histograms", "empty values" instead of "empty ranges").

- Added the reverse mixed-direction tests (multirange x range).

Regards,