Split bill before transaction (pre-auth)

You are trying to organise an event, buying tickets or whatever and you want to now who is locked in, who wants to make the purchase.
You send out a Monzo split, find out who is in and they pre-authorise the payment.
Time to make the transaction, I buy the tickets and choose the pre-auth pot. It’s done the waiting for people to pay me back is gone. Seamless.