Adjusting pools
Move somebody the auto-deal put in the wrong pool, and give a late arrival their first one.
When to use it
Pools are dealt automatically the moment the competition starts, round-robin across however many you asked for. That is a fair split, not a considered one — it does not know that two of the people it just dealt into the same pool played each other twice last month, or that a walk-in landed somewhere lopsided.
Move them before the first pool round is paired. Once it is, pools are sealed for anyone already in one — not because the deal was final, but because everyone in that pool has already started building a record inside it, and a move after that point would be rewriting who they were compared against.
A late arrival with no pool yet
Seating somebody after the event has started (see "The roster, walk-ins and drops") gives them no pool at all — the auto-deal only ever runs once, at the moment the competition starts, and a late arrival was not there for it. That is a different fact from an already-pooled player being moved, and the seal above was never protecting it: nothing about a player with no pool yet was ever scheduled, so there is nothing to rewrite by giving them a first one.
So this stays open the whole time the qualifying stage runs, not just before the first round is paired. The console shows them as unassigned and suggests the pool with the fewest players so far — a suggestion, not a decision, and you can always pick a different one before confirming.
What does not happen: the rounds their pool already played are not replayed for them. Their standings reflect fewer rounds played, the same way a drop or a bye already reads elsewhere in this product.
What it will not do
It will not let you move anyone who is ALREADY in a pool once the first pool round has been paired. Undo is not offered mid-stage the way a reseat is mid-round, because a pool is not one round's pairing — it is every round the stage plays, and there is no single match to reset first.