Cumulative END time (ms) of each segment; length = segments.count, monotonic non-decreasing.
hasUnknownFeedrate
hasUnknownFeedrate:boolean
True if any moving segment had an unknown feedrate or a non-finite length (contributed 0). The
estimate is then a lower bound / approximate — a consumer should disclose it (and prefer the slicer
estimate when present).
Cumulative END time (ms) of each segment; length =
segments.count, monotonic non-decreasing.