I did last year's Breckland 12 on 23mm Corsa Speed tubs. Deeply uncomfortable over the rutted sections on the A11 in the northern half of the course, but I didn't puncture or die. I know they've amended the course for this year, but I don't know what the changes are.
Got Breckland maps off their Facebook group via another FB account.
Anyone know what roads like? Was just gonna run Vitoria Corsa Speed 25mm and hope for the best.