The Gauge 0 Guild are exploring the modular layout concept. Here is a video from their recent “Virtual Show”. I believe they have commissioned a standard baseboard 750mm x 1200mm from Grainge & Hodder. I’m no longer a member, so don’t have further details.
I’ve just looked, and G&H do 400 and 600 x 1200, which are more suited to EM. There’s also a couple with the “Fremo” tag.