I've never been to LFCC but I've been to past Collectormania (Collectormania Glasgow now renamed as Glasgow Film & Comic Con) events both in Milton Keynes and my home city of Glasgow as well as the past DST events held in the ExCel centre in London.
I remember that a floor plan PDF file WAS put up on the forum in the week leading up to DST3.
I'm hoping for the same this time around too.
For those newbies out there, the souvineer programme available at the event, and included with the packages, usually has the floor plan.
Honestly don't remember floor plans going up for anything other than LFCC because of it's size! But you're right about them being in the brochures.
It was definitely online last time as I made smaller, laminated versions to attach to my plastic folder.