Takara Tomy Plarail Show Setup

If you watch the first vid some tracks overlap and it shows workers connecting two planks with rails.
My thinking is that they plan and assemble the layout at their shop to reduce the install and disassemble time at the show.

You are right, they do probably reuse panels depending on site size.
Now we just need a basketball size living room

If we win the lottery a train layout is required in our new home LOL