Interface PlanRequest

Whether a columns selector also assembles a widened TimeSeries.

Defaults to true, which is right for an in-process renderer: the chart layers take a series plus a column name, and assembling once is cheaper than making every consumer do it.

Pass false when the consumer is across a wire. Assembly there is pure waste — the series cannot be serialized, and the columns can, so the receiving side rebuilds one with TimeSeries.fromColumns, which adopts a Float64Array zero-copy. Measured at 1M rows, appendColumn costs 7.6 ms for a gapless column and 22.4 ms for a gapped one — and every rolling study is gapped ([PND-PROCCOL]).