The second delta review compared the filtered checks with the previous
implementation on 5,400 generated cases. Rapid checks matched in every
case, but 114 lead checks differed: a long lead passing a small circle
or arc well over 0.001 away was reported clear, while the native
line/circle query, through rounding in its squared terms, reports a
contact there. A coordinate limit and a fixed margin cannot bound that
cancellation.
Lead checks therefore examine every other part's material again,
exactly as before the filter; LeadMaterialSnapshot no longer keeps an
extent. Rapid checks, including the pre-post review's, keep skipping
completed contours more than 0.001 clear of the rapid. The 900000-long
lead beside a radius-0.0001 circle is a regression test.
Planning a dense 144-part grid now takes about 19 s again (lead checks
dominate); a new part order is still found where the old search gave
up.