Depends on what you consider “the point”…
okay, fair enough… but if you print the provided models on your printer, you kinda can. Granted it’s not porcelain and might not be your cup of tea (pun intended) but as far as putting some plants in… I mean it’s a model, right. Then if you’re happy with it and you want to keep the thing for yourself, you should of course get the real deal and not the 3D printed version of the Corcelain piece, so…
…I do agree that via MakerWorld would make it much more accessible, but as far as designing for the contest? I’m sure we got people on here that just printed a small Skadis board on their (worst case) 180x180 A1 Mini and design adapters for the system without owning an actual IKEA board.
What I’m trying to say, it’d be nice if down the road these pieces could be ordered through MakerWorld, but that really shouldn’t keep you from joining the contest. My two cents anyways…