With 55 years in the exhibition game, I have well learned that folks want to be entertained by a layout, that means action.
In a word, that means 'roundy roundy'..... set and forget, you get the picture. The purist shunting type layout is just that, for the purists (save it for club events).
I see too, that the modular crowds have finally discovered 'table top' presentation at long last. I've been through all the 'current trends' with modules, and long ago settled on organizer supplied standard tables, works both ways, I never tend to get rejections because of layout shape/size... just give me 6 (or how many) standard tables, I'll fill 'em, you can place them any way you want.
If it takes me more than 10 minutes to set up or dismantle at a show, then I'm too slow. That's for 5 layouts altogether, by the way. The one exception to the 10 minute rule, was the time I built, from scratch, at the venue, a Garden Railway.... that took about 30 minutes to build, and an hour to clean up afterwards. Most of that time was shovelling up the bark chips, and vacuuming the floor
I'd had this idea for some time, and decided to give it a go. I bought my own piece of carpet to lay it on, because, often, venues have wooden floors, and more often sports court markings (this venue acually carpets over to protect those floors). Track was put together by a 5 year old (that's his dad's 7/8ths stuff on the table). Two bags of bark chip formed the base scenery, the greenry was just some green stuff from the garden, and the structures 'borrowed from Taita Gorge'. I used battery power. The Coors wagon has a total of 14V packed in it, and the yellow car has the Basic Train Engineer receiver in it. Ran all day on one charge.