Just finishing my build, and it all went together almost perfectly — with the exception of the corner blocks (and roller locks), which were very tight. I’m using 25mm tube (chrome-plated wardrobe/closet rail), and while it fits perfectly into the roller assemblies, the corner blocks were a very tight fit. I did file down the holes a bit, but still ended up banging in the tubes into the corner blocks with a hammer.
It’s all snug, but the bottom of the blocks now sit at an angle. I only noticed this after gluing on the feet of course — which now aren’t vertical.
I guess I can fix my corner blocks without taking everything apart with a bit of a blast from a heat gun — but to deal with cases like mine (where the rail seems to be the right size, but the printed holes a re a bit tight, it might be a good idea to either make it clear in the instructions that it is worth spending more time filing…. or provide a parametric shim (e.g. in openscad) that can be glued onto the bottom of the corner blocks.