This image shows the result of interpolating two weights of a lowercase x. As you can see the interpolation in't very drastic. Both weights being interpolated had no curves. Yet one line ended up with a subtle curve.
Interpolation, bold or outline often produces dead curves on diagonals (see above image). They are not detected by FontAudit. Optimize won't get rid of them. I'm been manually deleting them for almost a decade. Thousands and thousands and thousands of them. Almost every glyph with diagonal lines produces at least one dead curve.
I would prefer not to spend another decade manually deleting dead curves. At the very least, teach Optimize how to remove them.
