I'm with HL and they offer a specific isa transfer service where they do the sell and the buyback within seconds of each other. Have used it many times. I'm sure most decent brokers do this.
Absolutely right. It is now nearly an hour and a half since 2p was first paid but we have certainly not 'broken' 2p yet, plenty of 1 9xxx sellers around. Still, who knows what this afternoon will bring.