In the wizard
On Knockout setup, the question What does everyone else play? is the plate switch: choose A Plate (n) and the players below the qualifying line get a knockout of their own, built in the same Create the brackets → as the main draw. The plate takes its own match format, and its own answer for what plate losers play — just the draw, a 3rd-place playoff, or full placement.
If you'd rather they play a second round-robin than a bracket, They drop into a new competition builds new blocks or a Swiss instead — a second flight rather than a plate.
Adding one after the brackets exist
✨ Rebuild the knockout re-opens the wizard; creating with the plate answered builds the family fresh — it replaces the current brackets rather than stacking a plate on top, so do it before knockout results exist. Once knockout games are underway, add the plate by hand instead: 🎛 Build brackets manually, kind Consolation / Plate, seeded from the block ranks below the line — the main draw is untouched.
When the field isn't a clean rank range
A rank range covers the usual plate — everyone below the line. It can't skip specific people, and it can't reach players outside the finishing order. When the real field differs — say three non-qualifiers decline, and five players who never played the qualifying stage join — build the plate with 🎛 Build brackets manually and the Pick players seed source: tick exactly who plays, from any of the event's competitions, and set the seed order by hand.
Players joining from outside the event go in through the Players tab first. In an event with more than one competition they can stay unplaced — they appear in the picker under Not placed in a competition — or be placed into a competition of their own (a player can hold entries in several competitions). Adding them to the qualifying competition itself would put them in its standings, so pick them into the bracket instead.
Scheduling it
The plate is a bracket like any other on Knockout schedule: give it its own lawn pool if the main draw owns the show lawns, and set where its final sits in the closing order.