I wasn't in Direct Select after all - just a basic misunderstanding. For some reason I thought that each preset contained settings for all the foot switches - now I realise that each bank can contain 1 preset for each switch and pedal.
So, yes! I was missing something very basic and now it all makes sense (we'll see how I get on in practise!).
For the record my primary wish for the FCB is to control my DAW's transport controls with my feet so that I can keep my hands on my guitar when recording - and I have now achieved this.